Talks between Theresa May and Donald Trump were an "indication of the strength and importance of the special relationship between our two countries," May said at a joint press conference between the two leaders today.
The pair said they planned to discuss Nato and a state visit by Trump to the UK later this year - but said one of the main focuses today's talks, which are only half-way through, will be on establishing trade agreements between the two countries.
"We will identify practical steps we can take now in order to enable companies based in both countries... to trade more easily," said May.
"Trade between our two countries is worth £150bn plus. The US is the single biggest source of investment into the UK," she added, saying a deal between the two countries is in the "national interests of both".
Meanwhile, Trump pledged "lasting support to this most special relationship", adding that Brexit was "a tremendous asset, not a tremendous liability".
The pair also discussed defence, with May saying the pair were "united in our recognition of Nato and the importance of it continuing".
Asked where May and Trump's views differed, May again cited the special relationship.
"I've been listening to the President and the President has been listening to me. That's the point of a dialogue," she said.
"There will be issues on which we disagree. The point of the special relationship is that we are able to have that open and frank discussion.
The pound remained lower against the dollar after the conference, falling 0.44 per cent to $1.2542.