Liz Truss held her first official meeting with Joe Biden on Wednesday night as it emerged that Britain has set a six-month deadline to solve the impasse around the Northern Ireland Protocol.
Success could also pave the way for a major visit by the US president to the UK next April, as he is believed to want to take part in events celebrating the 25th anniversary of the Good Friday Agreement.
Meeting in New York, the Prime Minister and the US president discussed issues around the Protocol, which has plagued relations between the UK and Ireland since the signing of the Brexit withdrawal agreement.
The Northern Ireland Executive is currently suspended after the Democratic Unionist Party (DUP) withdrew from Stormont as a result of its objections to the Protocol.
British officials believe they have until the silver anniversary of the Good Friday Agreement, which was signed on April 10 1998, to solve the Protocol issue; a move which would allow the restoration of the Northern Ireland institutions.