Macron personally invited the prime minister, to mark the 120th anniversary of the Entente Cordiale between France and the UK, which paved the way for greater diplomatic cooperation between the two countries.
The statement said the two leaders had reaffirmed their commitment to “support Ukraine unwaveringly and for as long as necessary to thwart Russia’s war of aggression”.
A further statement from Downing Street said the pair discussed how to put Ukraine in “the strongest possible position going into the winter”.
There were no details on whether the two leaders would support allowing Ukraine to use long-range Storm Shadow missiles deep into Russian territory.
The key decision-maker as far as London and Paris are concerned remains President Biden – who has so far have not given Ukraine permission to use long-range missiles against targets inside Russia, for fear of escalation.
Downing Street said “no war was ever won by a single weapon” when asked whether the UK was speaking to President Biden about the potential use of the missiles.
A Number 10 spokeswoman said: “Our position on Storm Shadow hasn’t changed.
“We’ve always aid that where we discuss our support for Ukraine, we do so in terms of broader strategy to ensure that Ukraine is in the strongest possible position going forwards, particularly in the winter, and we’ve also been clear that no war was ever won by a single weapon.”
Questions have been raised following Trump’s presidential election victory about what his second term could mean for US support for Ukraine and Nato.
Over the weekend, the Washington Post reported, external Trump has already spoken to Vladimir Putin – urging the Russian leader not to further escalate the war.
The Kremlin denied a phone call took place, claiming the Washington Post’s article “does not correspond at all to reality”.
Macron thanked Sir Keir for being the first British leader at the Champs-Élysées ceremony since Winston Churchill in 1944.
During the Armistice Day commemorations, Sir Keir also met French Prime Minister Michel Barnier before observing a minute’s silence.
Sir Keir and Macron laid a wreath at the statue of Churchill in Paris and travelled in an open roof car to review troops around the Arc de Triomphe.
During their meeting, Sir Keir and Macron also committed to “cooperation on migration in the Channel, particularly in the face of human trafficking networks,” a statement said.
The pair discussed European security and “the prospects for the relationship” between the EU and the UK, alongside discussions the humanitarian situation in Gaza.
“Finally, the two leaders reiterated their desire to deepen bilateral relations, particularly in the areas of security and defence,” the statement said.