Sir Keir intends to press Donald Trump for a ceasefire in Gaza and to alleviate the suffering of Palestinians, amidst growing calls for the UK to recognise Palestine as a state.
The mini-summit follows a bilateral meeting between Donald Trump and European Commission president Ursula von der Leyen, where a trade deal was agreed.
The meeting takes place against a backdrop of intensifying debate over the Middle East crisis, including a public disagreement between Sir Bob Geldof and Kemi Badenoch regarding aid to Gaza.