They weren't just delighted with the optics of the two leaders chatting about their families and the royals over winter greens and sea bass – Sir Keir's team believed they had made genuine progress in talks in the Oval Office about Ukraine.

Foreign Secretary David Lammy played the US president as the Prime Minister and his team 'war-gamed' how to handle the high stakes meeting.

President Donald Trump and British Prime Minister Keir Starmer met at the White House on Thursday for their first in-person talks since the Republican leader upended U.S. policy on Ukraine, the Middle East and global trade.