World leaders at the G20 summit are at odds over how to tackle climate change – with France threatening to veto any final communique if the US waters down the language.
Theresa May is attending the summit in the Japanese city of Osaka, and is challenging her counterparts to mount an urgent international response to the climate crisis by setting their own targets for cutting greenhouse gas emissions.
While the prime minister wants “the strongest wording we can deliver”, US President Donald Trump may prove to be a sticking point.
Sky News’ diplomatic editor, Dominic Waghorn, said: “Sparks have been flying all night.
“The sherpas, who are the negotiators who meet together to thrash out the words which all the leaders will sign at the end, had a long night, and the final communique is still being argued over, a British government source has told us.
“At the heart of that disagreement is an American objection to the language about climate change, an issue which Theresa May is going to lead the intervention on, about more concerted international action.
“But that is going to be stymied by what Mr Trump is trying to do.
“In the past, they have got round this by saying the rest of the G20 supports stronger action on climate change but understands that America does not.
“We understand that French President Emmanuel Macron has said he will veto the communique if that happens this time – so a nail-biting finish.”
A British government official told Press Association: “I think it was a long night for the sherpas and I think it’s definitely a challenging process but work is ongoing in relation to the communique so we’ll have to see where we end up.
“There have been a number of areas, trade is obviously one, climate would be another.”
Mrs May is using her last G20 summit as prime minister to tell other leaders she will use the aid budget to help tackle climate change and will urge other nations to follow the UK’s commitment to cut greenhouse gases to net zero by 2050.
She is expected to say: “The facts, which are clear, should guide us: we are running out of time to act.
“In addition to stronger national commitments, we need determined implementation, and a change in how we invest.”
The prime minister will also lobby leaders as part of a bid for the UK to host the next international climate conference.
Mr Trump appears to have been preoccupied with an offer to meet North Korean leader Kim Jong Un at the demilitarised zone (DMZ) between North Korea and South Korea this weekend.
During a meeting with Saudi Arabia’s Crown Prince Mohammed bin Salman at the G20 summit, Mr Trump said he “put out a feeler” to organise a meeting with the North Korean leader.
The US president is currently in Osaka for the summit but will travel to South Korea on Saturday and return to Washington on Sunday.
He also tweeted an invitation to Mr Kim, writing: “After some very important meetings, including my meeting with President Xi of China, I will be leaving Japan for South Korea (with President Moon).
“While there, if Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)!”
Speaking to reporters, Mr Trump repeated his long-running claim that he and Mr Kim “get along very well” – and said he was responsible for preventing a war with North Korea.
He added: “It’s good to get along (with Kim Jong Un) because frankly if I didn’t become president (the US would) be right now in a war with North Korea.
“And by the way that’s a certainty. That’s not like maybe.”
The US president admitted he did not know where Mr Kim is currently and said he “may not be in North Korea”.
Mr Trump is set to meet South Korea’s President Moon Jae-in over the weekend and travel to the demilitarised zone, which he described as a “real border”.