US President Donald Trump is poised to pull the country out of the Paris climate accord, US media report, quoting senior officials.
The American leader refused to reaffirm his country's commitment to the accord at a G7 summit in Italy on Saturday.
He said he would make up his mind after returning to the US.
Mr Trump, who has called climate change a "hoax" on occasion, has reportedly indicated this is still his position to key members of his inner circle.
News that Mr Trump was moving towards quitting the agreement was reported by the Axios news website and ABC News.
In response, German government spokeswoman Ulrike Demmer was quoted by Reuters news agency as saying: "Like you I've seen the reports but I don't have any information beyond that.
"So I can only reiterate the well-known position that the German government unequivocally supports the Paris climate agreement and is campaigning for it to be quickly implemented and hopes the USA remains committed to this agreement."