Paris and Washington pledged Wednesday to reenforce their cooperation in space, particularly on exploration and climate, during a visit by France's Emmanuel Macron to NASA headquarters alongside US Vice President Kamala Harris.

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.

SpaceX on Wednesday postponed the launch of the world's first private lander to the Moon, a mission undertaken by Japanese firm ispace.

A Falcon 9 rocket was scheduled to blast off at 3:37 am (0837 GMT) on Thursday from Cape Canaveral in the US state of Florida, but SpaceX said further checks on the vehicle had led to a delay.

"After further inspections of the launch vehicle and data review, we're standing down from tomorrow's launch of @ispace_inc's HAKUTO-R Mission 1; a new target launch date will be shared once confirmed," the firm tweeted.

Until now, only the United States, Russia and China have managed to put a robot on the lunar surface.

The mission by ispace is the first of a program called Hakuto-R.

The lander would touch down around April 2023 on the visible side of the Moon, in the Atlas crater, according to a company statement.

The delay came after the launch had already been postponed by a day due to the need for additional pre-flight checks, SpaceX and ispace said on Wednesday.

Measuring just over 2 by 2.5 meters, the lander carries on board a 10-kilogram rover named Rashid, built by the United Arab Emirates.