The Joe Biden administration submitted a letter to the United Nations that formally triggered a 30-day process to reenter the Paris climate agreement. The announcement came hours after Biden was sworn in as the 46th US President on Wednesday.

“He rejoined the Paris climate agreements, putting the United States back and a position to exercise global leadership and advancing the objectives of the ambitious agreement,” White House Press Secretary Jen Psaki said in her first briefing to the media.

Experts say that after four years under Donald Trump, the Democrat will have to rebuild the credibility the US lost in the eyes of the international community, by setting concrete goals for its emissions reductions on the path to net-zero by 2050.

Biden took the first steps towards addressing the climate change issue. Along with rejoining the Paris accord, Biden also passed a broad executive order to rollback harmful regulatory reversals made by the previous administrations to protect public health and the environment.

“This order reviews the boundaries are several national monuments, placing a temporary moratorium on all oil and natural gas leasing in the arctic and the national arctic wildlife refuge, and reestablishes the interagency workgroup on greenhouse gases,” Tsaki said.