PARIS -- French President Emmanuel Macron Saturday hailed the efforts of the European Union and China in the past years to advance the Paris Agreement and welcomed "back home" the United States in this global endeavor for which "action must be immediate."

"We have continued to go forward, to work together despite the American choice," Macron said at the Climate Ambition Summit 2020 co-convened by the United Nations, Britain and France.

He referred to the decision made in 2017 by outgoing US President Donald Trump to pull out of the legally binding Paris deal adopted in 2015 with an aim to strengthen the global response to the threat of climate change.

"I really want to hail the European mobilization and the formidable cooperation during these years with China," added the French president.

Macron also welcomed the decision of US President-elect Joe Biden to rejoin the Paris Agreement. "Welcome back, welcome home!" he said.

"We do not have a lot of time ahead of us and the action must be immediate," Macron noted. "We must give ourselves a path and credible means to achieve carbon neutrality by 2050."

The Paris Agreement, adopted by 196 parties at the 2015 Paris Climate Conference (COP21), came into force on Nov

4, 2016. Its goal is to limit global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, compared with pre-industrial levels.

To achieve this long-term temperature goal, countries aim to reach global peak of greenhouse gas emissions as soon as possible to achieve a climate neutral world by mid-century.

At the ongoing one-day Climate Ambition Summit 2020 held via video conference, countries are expected to set out new and ambitious commitments to the COP26 in November next year in Glasgow, Britain.