The French president, on a state visit to the United States, highlighted the American lunar program Artemis, whose first uncrewed test mission launched in mid-November with participation of the European Space Agency (ESA).

"We are very keen" to participate, he told Harris, adding with a smile: "It's very important for us, as long as you can propose a French leader to fly to the Moon quite rapidly," he said, in a nod to French astronaut Thomas Pesquet, who joined Macron for the NASA visit.

The two ally nations are also collaborating on the recently launched James Webb Space Telescope, whose initial images have already shaken up our understandings of the universe.

On the climate front, Macron mentioned the scheduled December 12 liftoff of the Surface Water and Ocean Topography (SWOT) mission, a NASA satellite developed in partnership with France's CNES which aims to monitor the levels of oceans, lakes and rivers.

"We are so very proud to work with France," Harris, who chairs the White House's National Space Council, said, noting how the two countries have partnered on space exploration for more than 60 years.

"In this time, we have made great strides and yet in so many ways we are beginning a new journey together," she said.

When she visited Paris last year, the deputy to President Joe Biden joined Macron to "launch a strategic dialogue on space," the French leader recalled.

With Macron suggesting that outer space could become a point of international contention, he and Harris stressed the importance of developing new norms of conduct in space.

France in June joined the Artemis accords promoted by the United States -- a series of principles governing conduct in deep space by different nations. The policies are aimed at deconfliction of activities, implementation of safety zones, registration of space objects and coordination on emergency assistance.

On Tuesday France also pledged not to conduct anti-satellite missile tests, which cause space debris that can then threaten orbiting spacecraft and satellites. The United States made the pledge earlier this year.