The prime minister will try to convince Mr Trump to uphold security guarantees for Kyiv and ensure Volodymyr Zelensky has a role in discussions to end the war.
The health secretary told Times Radio: "The prime minister will be travelling to France to meet with other European Nato leaders to discuss what is a once-in-a-generation moment for the collective security of our continent, which isn't just about the future of Ukraine, it is an existential question for Europe as a whole.
The meeting in Paris called by Mr Macron will see Sir Keir joined by leaders from Germany, Italy, Poland, Spain, the Netherlands and Denmark along with the presidents of the European Council and European Commission and the secretary general of Nato.
Sir Keir Starmer will seek to act as a bridge between Europe and the United States as he urges Donald Trump not to freeze Ukraine out of peace talks with Vladimir Putin over the war.
But he said that along with military aid to Ukraine “it also means being ready and willing to contribute to security guarantees to Ukraine by putting our own troops on the ground if necessary”.
