Joe Biden said he intends to visit Northern Ireland after being invited to mark the anniversary of the Good Friday Agreement.
The US president was speaking after Rishi Sunak formally invited him to make the trip to mark the 25th anniversary in April as the pair held talks in San Diego.
As the pair met in Point Loma naval base, Mr Biden said: “It’s my intention to go to Northern Ireland and the Republic.”
Mr Sunak told the president: “I look forward to our conversations and also importantly, to invite you to Northern Ireland, which hopefully you will be able to do and so we can commemorate the anniversary of the Good Friday Agreement.
“I know it’s something very special and personal to you. we’d love to have you over.”
Mr Biden said: “Twenty-five years? It seems like yesterday.”
The US president joked about Mr Sunak’s home in Santa Monica as the pair met following the announcement of the Aukus submarine pact.
“First of all, I want to welcome you back to California. He’s a Stanford man, and he still has a home here in California,” he said.
“That’s why I’m being very nice to you, maybe you can invite me to your home in California. But all kidding aside, I think it’s an historic day for our countries.”
Ahead of their talks, Mr Sunak dampened any hopes that he could get the president to reopen negotiations on a post-Brexit free trade deal with the US.
The Prime Minister insisted transatlantic trade was “growing massively anyway” as he praised pacts with individual states ahead of his meeting with the US president in San Diego on Monday.
A free trade deal with the world’s largest economy had been touted as one of the prizes of leaving the European Union but negotiations have stalled.
Mr Sunak insisted his new Windsor pact with the EU was a “great step forward” for Northern Ireland, following hopes it could ease tensions with Democrats in the US and pave the way for trade talks.
But the Prime Minister downplayed the focus on a free trade deal with the US, telling GB News: “America is always, and has always been for a long time, our closest economic relationship, it’s our single biggest trade partner.”
Asked if the trade deal is off the table, Mr Sunak said: “It’s just people should actually know that our relationship with America economically is very strong, our exports are growing massively anyway and we’re concluding agreements with states.”