US President Donald Trump has said he expects a "powerful" trade deal with the UK to be completed "very quickly".
Speaking at the G20 summit in Hamburg, he said he would go to London. Asked when, he said: "We'll work that out".
The US president is holding talks with UK Prime Minister Theresa May to discuss a post-Brexit trade deal.
It is one of a series of one-to-one meetings with world leaders which will also see Mrs May hold trade talks with Japanese Prime Minister Shinzo Abe.
Ahead of their meeting, Mr Trump hailed the "very special relationship" he had developed with Mrs May.
"There is no country that could possibly be closer than our countries," he told reporters.
"We have been working on a trade deal which will be a very, very big deal, a very powerful deal, great for both countries and I think we will have that done very, very quickly."
Sir Christopher Meyer, a former British ambassador to Washington, said Mr Trump's statement of intent was a "very good sign for the future" and would be "useful" to Mrs May.
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But Sir Simon Fraser, a former diplomat who served as a permanent under-secretary at the Foreign Office, cast doubt on how soon any trade deal could be reached.
"The point is we can't negotiate with them or anyone else until we've left the European Union.
"And the Americans and others will not negotiate with us until they know what our relationship with the EU is going to be, because the access we have in Europe is hugely important for the advantages that they can get from their relations with us."
The BBC's diplomatic correspondent James Robbins, in Hamburg, said Mr Trump was known to have accepted an invitation to visit the UK - a prospect that has caused huge controversy - but no clarity was given on when that might happen.