AMSTERDAM- The United States is "proud to be back" in international efforts to slow climate change, Washington's new special climate envoy John Kerry told a summit of leaders on Monday.

President Joe Biden's administration is this week expected to release more policies it believes are needed to tackle climate change after rejoining the 2015 Paris climate agreement that predecessor Donald Trump quit saying it was too costly to the U.S. economy. 

"We're proud to be back. We come back with humility for the absence over the last four years and we will do everything in our power to make up for it," Kerry told the Climate Adaptation Summit by video link.

Kerry was joined by China's Deputy Prime Minister Han Zheng, German Chancellor Angela Merkel, French President Emmanuel Macron, British Prime Minister Boris Johnson and other leaders.

"President Biden has made fighting climate change a top priority of his administration. We have a president now, thank God, who leads, tells the truth and is seized by this issue," Kerry said.

Leaders stressed the importance of having Washington back at the table.

"Since I'm the first to take the floor after John Kerry, a warm welcome to the U.S. back in the Paris Agreement," said International Monetary Fund Managing Director Kristalina Georgieva. "To tackle this great challenge we need all hands on deck and certainly the U.S. is so critical for success."

The online event, hosted by the Netherlands, aims to set out practical solutions and plans for dealing with climate change in the period until 2030.

As secretary of state under former President Barack Obama in 2015, Kerry helped bring China to the table at the U.N. climate conference in Paris.

(Reporting by Bart Meijer; Additional Reporting by Toby Sterling; Writing by Anthony Deutsch; Editing by Alex Richardson and Alison Williams) ((Bart.Meijer@thomsonreuters.com; +31 20 504 5006; Reuters Messaging: bart.meijer@thomsonreuters.com))