US President Donald Trump's top economic adviser has told a United Nations meeting that the US is standing by its plan to abandon the Paris climate pact without a renegotiation more favourable to Washington, a step for which the international community has little appetite.

Trump announced in June that the US would withdraw from the landmark 2015 accord, saying it would harm US industries, cost US jobs, weaken American national sovereignty and put the country at a permanent disadvantage to other nations. He also raised the possibility of renegotiating it.

“We made the president’s position unambiguous, to where the president stands, where the administration stands on Paris,” Gary Cohn, director of the White House National Economic Council, told reporters after an informal breakfast meeting on Monday that also included ministers from a dozen countries and the European Union on the sidelines of the annual UN gathering of world leaders.

Cohn, who is overseeing the issue for Trump, declined to elaborate on terms that the US would consider suitable to remain in the accord. A White House official said the meeting included representatives from Argentina, Australia, Brazil, Britain, Canada, France, Germany, India, Italy, Japan, Mexico and South Africa, as well as the EU.

Cohn said the breakfast meeting was “very constructive” and the “mood was good,” adding, “Everyone wants to work together.”

A European official at the breakfast told Reuters Cohn made the same points on the US position that he made publicly but with a more positive, open tone. The official said Cohn indicated that the conditions that would keep the US in the accord did not exist yet.

There had been some uncertainty about the US stance after American officials attended a Montreal meeting on Saturday of ministers from more than 30 of the nations that signed the climate change agreement. The Wall Street Journal reported that Trump administration officials said Washington would not pull out of the agreement and had offered to re-engage.

“There was some confusion over the weekend and I think we removed all the confusion,” Cohn said, referring to the Montreal meeting.

US Secretary of State Rex Tillerson said on Sunday the US could remain in the Paris climate accord under the right conditions.