US President-elect Joe Biden is to nominate one of the leading architects of the Paris climate agreement as his climate envoy.
Ex-US Secretary of State John Kerry was one of several named for top positions by the Biden transition team on Monday.
It marks a big break with the climate policy under the Trump administration as Mr Biden makes good on his campaign pledge to tackle climate change.
Other key picks include long-time aide Antony Blinken as secretary of state.
Reports say former Federal Reserve chair Janet Yellen will be the choice for treasury secretary.
The nomination comes as calls are growing for President Donald Trump to concede the election.
He has made unsubstantiated claims of electoral fraud and is continuing to pursue legal challenges over the result.
Mr Biden is projected to beat President Trump by 306 votes to 232 when the US electoral college meets to formally confirm the winner on 14 December. This is far above the 270 votes he needs.
In a statement following the announcement on Monday, Mr Biden said: “I need a team ready on day one to help me reclaim America’s seat at the head of the table, rally the world to meet the biggest challenges we face, and advance our security, prosperity, and values. This is the crux of that team.”
Some of the positions require confirmation in the US Senate.