U.S. Secretary of State, John Kerry, hoped his presence at a Marrakesh conference to decide the finer points of an historic climate agreement would be a victory lap.

He said he was ready to cap off a year of negotiations that will result in global agreements to stave off the worst effects of climate change.

Instead, he found himself having to reassure delegates from almost 200 nations they could count on the U.S. to abide by the 2015 Paris agreement.

He said this in spite of the U.S. President-elect Donald Trump’s promise to withdraw the U.S. from the climate treaty.

“The president-elect is going to have to make his decision.

“What I will do is speak to the assembly about our efforts and what we are engaged in and why we’re engaged in it, and our deep commitment as the American people to this effort.

“I can’t speak to the (next) administration, but I know the American people support this overwhelmingly,” Kerry said on Tuesday to reporters.

Trump has called climate change a hoax, and said he would rip up the Paris deal, halt any U.S. taxpayer funds for U.N. global warming programmes, and revive the U.S. coal sector.

If he follows through on his promises, he would undo the legacy of President Barack Obama.

Obama has made climate change one of his top domestic and foreign policy priorities and called the trends of rising temperatures and other fallout from climate change “terrifying”.

A source on Trump’s transition team said this week that he was seeking quick ways to withdraw the U.S. from the Paris agreement, which seeks to reduce global greenhouse gas emissions.

The accord won enough backing to enter into force on Nov. 4, four days before the U.S. election, and the conference in Morocco started in part as a celebration of that landmark.