The US has indicated it will still take part in international climate talks despite withdrawing from the Paris Accord.
In a letter lodged with the UN, the Trump administration said it still planned to remove itself from the agreement that was hammered out with 200 other nations, but said it remained open to “re-engaging” on the issue.
“As the President indicated in his June 1 announcement and subsequently, he is open to re-engaging in the Paris Agreement if the US can identify terms that are more favourable to the United States, its businesses, its workers, its people, and its taxpayers,” said a letter from the State Department.
It added: "The United States will continue to participate in international climate change negotiations and meetings... to protect US interests and ensure all future policy options remain open to the administration.
"Such participation will include ongoing negotiations related to guidance for implementing the Paris Agreement."
Trump sparked widespread international criticism when he announced on June 1 that he had decided to pull the world's largest economy out of the painstakingly-negotiated accord, in line with his pledge to voters in last year's election.
Open to re-engaging?
While Trump said he was open to a renegotiation of the pact, the suggestion was swiftly shot down by fellow world leaders who said it was non-negotiable.
Speaking on a visit to Paris last month, Trump again raised the prospect of a change in policy by saying "something could happen" regarding US participation in the accord but gave no details.
Andrew Steer, president of the US non-profit World Resources Institute, said the letter implied a level of ambiguity that could indicate a desire to remain engaged.
"The United States could engage constructively in those negotiations on an issue such as transparency," he said.
"But a climate loner that is intent on withdrawing from the Paris Agreement will not be listened to if it aims to weaken or undermine the accord in any way."
The United States is the world's second biggest producer of greenhouse gases after China and its withdrawal was a seen as a body blow to the Paris agreement.
The accord commits signatories to efforts to reduce greenhouse gas emissions that cause global warming, which is blamed for melting ice caps and glaciers, rising sea levels and more violent weather events.
They vowed steps to keep the worldwide rise in temperatures "well below" 2°C from pre-industrial times and to "pursue efforts" to hold the increase under 1.5°C.
Despite notifying the UN of its intention to withdraw, the United States will not be able to formally pull out of the accord until 2020 at the earliest.
However, Trump has previously said his country would cease implementation immediately.