Joe Biden shook hands with Rishi Sunank as he arrived at 10 Downing Street for a meeting which could include discussions on cluster munitions and Ukraine’s bid to join Nato.
The talks kick off a busy day for the president, who is making a layover in London on the way to the Nato summit in Vilnius, Lithuania.
He will also meet King Charles III at Windsor Castle for tea and talks on the climate crisis.
Mr Biden’s trip comes after he defended the “difficult” decision to send cluster munitions to Kyiv.