The US has insisted it will leave the Paris climate accord, despite reports that it may be softening its stance.
Following a meeting of environment ministers on Saturday, the EU climate commissioner, Miguel Arias Canete, said Trump officials had indicated the US would either stay in the 2015 accord or review its terms.
But the White House insisted there had been “no change” in the US position.
In June President Donald Trump said the US would withdraw from the deal
He said it was part of his “solemn duty to protect America” and he would seek a new deal that would not disadvantage US businesses.
But opponents say withdrawing from the accord is an abdication of US leadership on a key global challenge.
The Paris agreement commits the US and 187 other countries to keeping rising global temperatures “well below” 2C above pre-industrial levels and “endeavour to limit” them even more, to 1.5C.
Only Syria and Nicaragua did not sign up to the deal.