US President-elect Joe Biden introduced his climate and energy team on Saturday, a history-making group that will seek to advance an ambitious climate agenda that reverses many Trump administration policies. 

Michael Regan would become the first Black man to run the Environmental Protection Agency (EPA) if confirmed by the Senate, and US Representative Deb Haaland, as interior secretary, would be the first Native American Cabinet member.

"Today's nominees are ready on day one, which is essential because we literally have no time to waste," Biden said at a media briefing in his home state of Delaware.

Biden, a Democrat who will be inaugurated on Jan. 20, has vowed to make tackling climate change a top priority. But with a slim majority in the House of Representatives and control of the Senate still undecided, his agenda may see little success in Congress and instead rely on rules from his regulatory agencies to enact sweeping change.

Biden, who served as vice president to President Barack Obama, tapped Obama's EPA administrator, Gina McCarthy, to fill a new role as national climate adviser.

Former Michigan Governor Jennifer Granholm will be Biden's energy secretary if confirmed.

Environmental groups have largely praised the team for its experience and diversity. But the powerful fossil fuel industry, which Biden has frequently criticized, has argued he must balance climate efforts with preserving jobs.

Biden wants the US to achieve net-zero greenhouse gas emissions by 2050, which would require the world's second-largest emitter to transform its economy including transportation, power generation and farming.

He diverges sharply from President Donald Trump, who withdrew Washington from the Paris climate accord and softened or dismantled climate regulations the administration deemed harmful to the economy.

Trump on Saturday continued to falsely assert on Twitter that the election had been stolen from him through voter fraud.