Paris: US President Donald Trump is holding the door open to a reversal of his decision to pull his country out of the Paris climate accord, but did not say what he would need in return to persuade him to do so.

Trump, who has made few friends in Europe with his rejection of the 2015 Paris agreement and his "America First" trade stance, met with French President Emmanuel Macron in Paris on Thursday as both leaders sought common ground to reset an awkward relationship.

"Something could happen with respect to the Paris accords, let's see what happens," Trump told a news conference. "If it happens, that will be wonderful, and if it doesn't, that'll be OK too."

Trump has said the Paris accord is soft on leading polluters like China and India, putting US industry at risk.