The United States is lifting its decades-old ban on imports of British lamb, Boris Johnson has announced.
The PM, who is in the US for talks with UN leaders and President Joe Biden, said the ban was "unjustified".
But he admitted the UK was now focused on making "incremental steps" on US trade access, rather than aiming for a full agreement.
Mr Biden appeared to play down the chances of a wider deal during a meeting with Mr Johnson on Tuesday.
Speaking to reporters on Wednesday, Mr Johnson said the Biden administration "is not doing free trade deals around the world right now".
But he added he had "every confidence that a great deal is there to be done".
Labour's deputy leader Angela Rayner mocked the lack of movement, saying the PM had made "absolutely zero progress" on a trade deal during his US trip.
The United States has banned British lamb imports since 1989, following the first outbreaks of BSE, commonly known as mad cow disease.
A similar ban on British beef imports, imposed in 1996, was lifted in September last year.
There is no indication yet of when the US will start accepting lamb and lamb products from the UK, and an official announcement has not been made.
The US Department for Agriculture has been consulting on lifting the ban since 2016 - and there were originally hopes it would be lifted the following year.
At the time, the UK government estimated the change would be worth an extra £35m a year to the UK economy.