Donald Trump's National Security Adviser H.R. McMaster said early Sunday that the United States could "certainly" stay in the Paris Agreement, "if there's an agreement that benefits the American people".
The Paris agreement, a landmark 190-nation agreement to reduce earth-warming gases, was struck in 2015.
China's special representative for climate change affairs, Xie Zhenhua, emphasized the importance of pushing forward with the deal, in spite of the recent blow from the Trump administration announcing its plan to bow out. "Of course, that withdraw can't take place until 2020".
Opponents say withdrawing from the accord is an abdication of United States leadership on a key global challenge.
But other advisers seemed to send more mixed messages.
This backs up reports on Saturday suggesting Mr Trump had softened his attitude towards the agreement.
McMaster said Trump was committed to the cleanest water and air on Earth and a strong clean energy policy, but he felt those priorities were not reflected in the Paris agreement.
Speaking in the White House Rose Garden, he characterised the Paris agreement as a deal that aimed to hobble, disadvantage and impoverish the US.
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"He told me he was going to try to find a solution in the coming months", French President Emanuel Macron said after meeting Trump in Paris in July. He said then that he could revisit the decision if the United States could renegotiate terms he sees as unfair.
Secretary of State Rex Tillerson also attempted to thread the needle, saying Trump would not entirely rule out staying in the agreement.
Speaking to United States network CBS, Mr Tillerson suggested the USA might not leave at all.
Bloomberg reported that the USA is "no longer seeking to withdraw from the pact and then renegotiate it, but rather wants to re-engage with the Paris Agreement from within".
It turns out the U.S. isn't pulling out of the Paris climate agreement after all. After being directly asked, Mr Tillerson said the USA could remain the accord "under the right conditions".
Trump drew global criticism when he declared the US would pull out of the Paris Agreement and seek a renegotiation.
That would contradict Trump's promise in June that he would pull out unless it was either renegotiated or scrapped and started again.
Since then, the president has teased that the United States could remain in the agreement. "If you look at those targets in terms of the Paris climate accord, they were just really out of balance for the two largest economies".