Nicaragua has signed the Paris climate agreement, meaning that the US and Syria are the only two countries not to be giving the accord their support.
The deal unites the world’s nations in tackling climate change. Nicaragua refused to sign it last year, arguing that it did not go far enough to tackle the problem.
In June President Donald Trump said the US would withdraw from the deal, but the rules of the agreement state that this cannot be done until 2020.
The president said it was part of his “solemn duty to protect America” and he would seek a new deal that would not disadvantage US businesses.
Scientists point out that work to implement the Paris accord must be stepped up if it is to have any chance of success.
The agreement commits the US and 187 other countries to keeping rising global temperatures “well below” 2C above pre-industrial levels and “endeavour to limit” them even more, to 1.5C.