The United States begins the step of the Paris Agreement

That the United States formally notifies the UN of leaving the agreement starts a process in which the country has done so in a year's time.

The global climate agreement was signed at the COP21 summit in Paris in 2015, and aims to increase the ambitions of reducing greenhouse gas emissions and limiting global warming - to reach the so-called 1.5-degree target, which is increasingly distant, according to forecasts.

US President Donald Trump has promised earlier that the US will step down from the agreement, saying that this will benefit the country's oil and coal industries. When Secretary of State Mike Pompeo now announces that the process is beginning for him, like Trump, to point out that the agreement poses an "unfair financial burden" for the United States.

He describes the country as a "world leader" in reducing emissions, boosting growth and securing Americans' energy needs, in a post on Twitter:

"Our model is a realistic and pragmatic one."

When Trump's predecessor Barack Obama signed the agreement, he promised that the United States would cut greenhouse gas emissions by 26-28 percent by 2030, compared with 2005 levels.

Donald Trump has repeatedly relativized US emissions against China. The United States and China are the two countries that account for the largest emissions.

"What we will not do is to punish the American people while making foreign polluters richer," Trump said on October 23, speaking at a conference held by the shale gas industry.

COP25 will be held in Spain at the beginning of December, following Chile's relinquishing of the host because of the troubled situation prevailing there.

The United States will leave the agreement entirely on November 4 next year, the day after the country's next presidential election.