Sir Keir, who is believed to be the first British leader to attend a ceremony on the Champs-Elysées since Winston Churchill in 1944, will also meet French Prime Minister Michel Barnier.
After Trump won the US presidential election, questions arose about what his second term might mean for US support for Ukraine and NATO.
Britain and France have said that supporting Ukraine against Russia is essential when it comes to the defense of the European continent as a whole.
Trump previously ordered NATO members to increase defense spending, saying he would let aggressors like Russia do “what the hell” to those who don’t.
During his campaign, Donald Trump refused to specify how he would end the war between Russia and Ukraine in one day, but it could involve forcing a deal on both sides.
Brian Lanza, who worked on Trump’s 2024 presidential campaign, told the BBC that Ukrainian President Volodymyr Zelensky should have “a realistic vision of peace”which does not involve stopping the Russian annexation of Crimea.
However, a spokesman for Donald Trump pushed him back on those remarks, saying Mr Bryan “doesn’t speak for him”.
The meeting between Starmer and Macron on Armistice Day comes as fighting between the two sides intensifies.
Weekend exchanges have seen the largest drone attacks by both sides against each other since the start of the war, and Russia’s Defense Ministry said it had intercepted 84 Ukrainian drones in six regions, including some approaching Moscow.
On Sunday, Finance Minister Darren Jones told BBC One Sunday with Laura Kuensberg that the government wanted to increase defense spending from 2.3% to 2.5% of national income.
However, he did not say when the goal would be achieved or whether it would be achieved before the next election, which could be as early as 2029.
Sir Keir joined other political leaders and members of the royal family, including the Prince and Princess of Wales, at the annual National Service of Remembrance ceremony at the Cenotaph in London on Sunday.
King Charles honored the nation with two minutes of silence in memory those who died during the two world wars or other conflicts.
As on Remembrance Sunday, two minutes of silence will be observed on Armistice Day at 11:00 GMT.
It marks the end of the First World War, at 11:00 on the 11th day of the 11th month in 1918.
