By Timothy Gardner and Valerie Volcovici

WASHINGTON (Reuters) – U.S. President-elect Joe Biden named former Secretary of State John Kerry as special climate envoy, his transition team said on Monday, a sign that Biden views diplomatic skills as vital to the job.

Kerry will have a seat on the National Security Council in the White House, the transition team said, marking the first time an official will be dedicated to the issue in that body.

Biden has pledged to reverse course on climate from President Donald Trump, who doubts mainstream climate science. Trump pulled the United States out of the 2015 Paris agreement on climate, and dismantled Obama-era climate and environment regulations to boost drilling, mining and manufacturing.

While secretary of state under former President Barack Obama, Kerry, 76, called climate change “the world’s most fearsome weapon of mass destruction.” In travels from glaciers in Greenland to the Solomon Islands, Kerry has emphasized cooperation on tackling climate change.

He will face a challenging task of gaining the world’s trust after Trump’s rejection of climate diplomacy. As Trump blasted the Paris agreement as being too expensive for U.S. citizens, China, the world’s top greenhouse gas emitter, positioned itself as a catalyst on climate, announcing new targets to cut the pollution in September.

Before the landmark Paris agreement, Kerry pushed for China and the United States, the world’s second-leading emitter, to agree on emissions targets and work toward a global deal.

Kerry, who was also a longtime liberal senator from Massachusetts and 2004 presidential candidate, will likely get a quick start as Biden has pledged to rejoin the Paris agreement soon after he comes into office. Unlike Trump, Biden believes climate change puts national security at risk because it leads to regional instability that will require more humanitarian missions by the U.S. military.

To help push countries to transition away from coal, oil and , develop renewable power and advanced batteries, as well as conserve delicate ecosystems like forests, Kerry will likely go beyond advocating for action under the United Nations framework for climate.

Kerry will also likely work with a counterpart in the White House, expected to be announced soon, focused on domestic climate issues.

“The challenge now is to really amplify and supercharge climate diplomacy not through negotiations, but making sure it is part of every country’s recovery from COVID and making sure it is a central pillar of policy,” said Nat Keohane, who heads the climate program at the Environmental Defense Fund nonprofit.

Appointing Kerry as climate envoy “sends the strongest possible signal about the importance of climate action to the incoming administration,” said Paul Bodnar, who was a senior director for energy and climate under Obama.

Late last year, Kerry launched World War Zero, a bipartisan group of world leaders and celebrities to combat climate change.

After Monday’s announcement, Ron Klain, Biden’s incoming chief of staff, said “Stay tuned!!” on Twitter, when Varshini Prakash, director of the Sunrise Movement environmental group, said she was keeping her eyes peeled for the naming of Kerry’s domestic climate policy counterpart.