US President Joe Biden has criticised the leaders of China and Russia for not turning up at the COP26 Climate Summit.
Neither Russian President Vladimir Putin nor Chinese leader Xi Jinping are at the Summit.
Both countries however have sent delegations to the talks, which are due to run for two weeks until 14 November.
China is the world's largest emitter of carbon dioxide, followed by the US. Russia is the fifth largest after the EU and India.
In a speech on Tuesday night, Mr Biden said climate was "a gigantic issue" and China "walked away" - adding it was the "same thing with Russia and Putin".
The US President then went on to attack Russia for not committing to ambitious climate goals.
President Biden also suggested that "China has lost influence" in not accepting the invitation to attend the event.
"America showed up and decided to lead," he added.
"By showing up, I think we had a profound impact on the way, I think, the rest of the world is looking at the United States and its leadership," he told the news conference in Glasgow.
"I think it has been a mistake, quite frankly, with respect to China, not showing up.
"They have the lost the ability to influence people around the world and here in COP. The same way I would argue with Russia."
Asked why the US should set such ambitious targets when nations such as Russia and China do not, he told reporters: "Because we want to be able to breathe."
More than 120 leaders turned up at the conference in Scotland's largest city.
Countries have already announced major deals, including a global pledge to slash methane levels by 2030 as well as to end and reverse deforestation by the same year.