Trump is asked if the billions of dollars in tariff revenue the US has taken since Liberation Day – which is when the US president announced his expansive tariffs last year – will have to be refunded.

"It wasn't discussed," Trump replies.

"I guess it has to get litigated for next few years," he says, before asking: "How crazy is that?"

He repeats that refunds were not discussed. "We'll end up in being court for five years," he adds.

Trump offers little detail on tariff planspublished at 18:50 GMT 20 February

18:50 GMT 20 February

Anthony Zurcher
North America correspondent

Donald Trump started this press conference with an extended diatribe against the court, calling the justices who ruled against him a “disgrace” and “fools and lapdogs”.

The president had appointed two of the justices in the majority, and it’s clear that their decision cut particularly deep.

The president isn’t abandoning the fight, however. As expected, he said that he would attempt to reimpose tariffs using presidential authority available under other laws. He has not, however, spelt out the details as of yet.

Whatever those alternatives may be, they will likely take time to implement. In the meantime, the president is left licking his wounds as a key pillar of his economic and diplomatic policy has been eroded.

Image source, AFP via Getty Images

Trump is now taking questions from reporters. He's asked if he will seek additional action from Congress on tariffs.

"No need to, it's already approved," he says, as the authorities exist under Section 232 and Section 301.

Trump says the Friday ruling did not overrule tariffs, just a specific use of the International Emergency Economic Powers Act, which according to the Supreme Court did not grant him the power he claimed to impose tariffs.

The president says that in an effort to "protect our country", he will charge more under other statutes.

Effective immediately, he says, he's signing an executive order to impose a 10% global tariff using section 122, which was created by the 1974 Trade Act

Previously imposed tariffs will remain in place and "in full force".

Trump returns to his previous point, saying that there are alternative methods he can use to impose tariffs.

He says the court's ruling declared he's not allowed to "charge one dollar to any country". He says he assumes this was done to protect other countries.

He says he is, however, allowed to cut off any and all trade or business or embargo a country.

"In other words, I can destroy the trade, I can destroy the country," he says, adding: "But I can't give them a little fee".

Trump digs in on tariffspublished at 18:33 GMT 20 February

18:33 GMT 20 February

Bernd Debusmann Jr
Reporting from the White House

Donald Trump began his surprise White House briefing by saying he finds the Supreme Court decision "deeply disappointing" and that foreign countries are celebrating – but won't be for long.

He has not backed away from tariffs and vows that he will use other mechanisms to get his way. Trump is clearly digging in, repeating his often-cited assertions that they are both good for the US economy and as a foreign policy tool.

I spend most of my professional life listening to Trump, often in the room. His tone today is different from usual, largely soft spoken. Many American observers expected his anger - which is clear - in more forceful language.

We have so far not heard much in terms of a specific "Plan B" for the administration's path forward.

Image source, AFP via Getty Images

Trump says there are other methods he can deploy to set tariffs other than the method the court has ruled against.

He says he has used tariffs over the past year to make America great again, before citing the Dow Jones and S&P stock indexes having "recently broken 50,000 on the Dow and 70,000 on the S&P".

The president then criticises the Nobel prize winners in economics, saying they argued "no, you couldn't do it in four years".

"Well we did it in one year," the president claims.

Image source, Bloomberg via Getty Images

Trump then accuses the Supreme Court of being "swayed by foreign interests", without providing any evidence.

He then pivots to his 2024 electoral victory, saying: "I won by millions of votes... but these people are obnoxious ignorant and loud. And I think certain justices are afraid of that, they don't want to do the right thing.

He adds: "This was an important case to me."

As a reminder, two Supreme Court justices nominated by Trump in his first term were part of the group that ruled against him in this case.

Trump goes on to thank and congratulate justices Thomas, Alito and Kavanaugh, all of whom dissented, for their "strength and wisdom".

He says there's no way no one can argue against the dissenting opinions.

He then calls the Democrat-appointed judges a disgrace.

Trump is at the podium now.

He starts off by telling reporters the Supreme Court's ruling was "deeply disappointing" and that he's ashamed of "certain members of the court for not having the courage to do what's right for our country".

We're about to hear from US President Donald Trump, who will be speaking to reporters at the White House after the Supreme Court struck down many of his global tariffs.

We'll bring you the key lines here, but you can also follow our stream by tapping Watch live at the top of this page.

Bernd Debusmann Jr
Reporting from the White House

It was a fairly quiet morning at the White House, even despite the news, with reporters wondering aloud when official reaction would come, and in what form.

We found out when we suddenly received word that Trump would be coming to the briefing room.

Within minutes, the White House was a hub of activity, with reporters rushing in, setting up cameras, and watching over their seats. It's already crowded.

When I came up to grab the BBC's seat, a White House staffer was affixing a presidential seal to the podium.

A last-minute presidential briefing is an extremely unusual occurrence, and shows just how significant the Supreme Court's decision is for the Trump White House.

The only other one that has taken place happened just days after Trump returned to office in January last year, when a plane collided with a helicopter over the Potomac River near Washington DC.

Jessica Murphy
Reporting from Toronto

Image source, Bloomberg via Getty Images

Canada’s US trade minister, Dominic LeBlanc, says the Supreme Court’s decision has reinforced his country's position that Trump's tariffs were "unjustified”.

But he adds that work remains to be done on the sectoral tariffs on the auto sector and on steel and aluminium, which have taken a toll on those industries.

He also nods to the review of the USMCA, known in Canada as CUSMA, the trilateral trade deal between the US, Canada and Mexico, saying: “We are working to create growth and opportunities on both sides of the border, while strengthening our collaboration with reliable trading partners and allies around the world".

The Trump administration has said it is weighing whether to scrap the trade deal, which has been in place in some form since the early 90s, and renegotiated in Trump’s first term, in favour of separate agreements with its northern and southern neighbours.

US President Donald Trump will hold a press briefing at 12:45 EST (17:45 GMT) on the Supreme Court's decision to strike down many of his tariffs.

Stick with us and we'll bring you the key lines here.

Trump unlikely to abandon trade agendapublished at 17:01 GMT 20 February

17:01 GMT 20 February

Daniel Bush
Washington Correspondent

The Supreme Court's tariff ruling today dealt Donald Trump a major setback on one of his signature economic issues. But it doesn't mean Trump's trade agenda will suddenly disappear overnight.

The Court ruled that the US president does not have the authority to levy sweeping global tariffs on any country, for any reason. Under the Constitution, that sort of power falls to Congress. But the ruling left in place some tariffs the US levied on specific goods from specific countries – offering the administration a roadmap to try to retool its tariffs policy.

In the past, Congress and the courts have given presidents leeway to impose tariffs on targeted goods, or for brief periods of time. For example, President Richard Nixon imposed a sweeping tariff on imports in 1971 to combat a currency crisis, but kept them in place for just four months. In 2003, President George W Bush imposed tariffs on steel imports and kept them in place for approximately nine months.

Had Trump followed that model closely, more of his tariffs may have survived legal challenges. The court ruling Friday may push the administration to revisit that approach, and look for ways to impose more targeted tariffs going forward.

Either way, Trump is unlikely to give up on an issue that has animated him for decades – since long before he ran for the White House. Trump has argued for years that the US needs an aggressive tariffs regime to compete with China and other economic rivals. He won't give that argument up easily, even if the Supreme Court just reined in his power to act alone on trade.

Mitchell Labiak
Business reporter

There is still a lot of uncertainty on how or if all US importers will get a tariff refund, but if they do, the cost to the US government could be huge.

According to the latest official data, external, US customs has collected over $130bn (£96.3bn) in import taxes from the the International Emergency Economic Powers Act (IEEPA).

Despite the ruling, economists have raised doubts about the likelihood of the US handing all of that money back. As Supreme Court justice Brett Kavanaugh puts it, the refund process is likely to be a "mess".

Jonathan Josephs
Business reporter

Image source, Getty Images

It’s worth reminding ourselves why President Trump wanted tariffs in the first place.

When he unveiled these tariffs last April he said “our country and its taxpayers have been ripped off for more than 50 years”.

He has taken the view that, because the US buys more goods from abroad than it sells, Americans' money is effectively leaving the country for no good reason.

The reality of a highly integrated 21st global economy is of course far more complicated.

That was demonstrated by the trade deficit reaching a new record high of $1.2tn last year despite the tariffs.

On top of that, he has wanted to bring back US manufacturing jobs but official figures show the number of Americans in that type of work has actually fallen slightly since he took office.

Trump has also wanted US companies to get better access to sell their goods abroad.

With that he has arguably had more success because to various degrees its been part of the trade deals he’s agreed, although those may now be in jeopardy.

Bernd Debusmann Jr
Reporting from the White House

Donald Trump has reacted to the Supreme Court's decision to strike down his tariffs, calling it a "disgrace".

He made the remark while speaking at a meeting with state governors earlier this morning, a source tells me.

We have yet to hear from Trump directly, or from White House officials. Trump has repeatedly said he views tariffs are hugely important to the US economy, and they very much form a key part of his wider agenda.

Danielle Kaye
New York business reporter

Trade lawyers are cautioning that while the Supreme Court's ruling opens the door to tariff refunds, businesses are still confronted with big questions about what form that process might take.

Steve Becker, head of law firm Pillsbury's international trade practice, tells the BBC that it will be up to the Court of International Trade to sort out the implementation of the court's ruling against Trump's tariffs.

The best thing for businesses, Becker says, is if the government were to announce an "orderly" procedure for obtaining refunds that does not require filing a lawsuit. "I think companies can be fairly confident that they'll get their money back eventually. But how long it will take really is up to the government," Becker said.

"There certainly will be a high volume and a lot of work involved," he adds.

But at the same time, Becker says it's likely the Trump administration has a contingency plan in place to impose tariffs through other authorities. That could mean, for example, using a law that allows the president to put tariffs of up to 15% in place for 150 days. He could also target specific countries or sectors.

Image source, Bloomberg via Getty Images

Even before the Supreme Court struck down Trump's authority to impose some of his global tariffs, some major US companies had sued to claw back what they had already paid.

In November, the multinational retail giant Costco became one of the largest importers to ask for a refund. Two lower courts had already ruled that Trump exceeded his authority by using emergency powers to impose tariffs.

In the lawsuit, Costco said its business had suffered because of the tariffs and was concerned it wouldn't get its money back even if the Supreme Court upheld previous rulings.

Others that have sued for refunds include Goodyear Tires, the Chinese electric vehicle maker BYD and camera makers GoPro.