U.N. climate chief Christiana Figueres says she will leave her post in July after six years in charge of the diplomatic effort to fight global warming.

The Costa Rican diplomat's announcement Friday comes two months after a historic international agreement on climate change was adopted in Paris.

In a letter to governments and observers of the talks, the 59-year-old Figueres said she would "not accept an extension" when her term ends in July.

Figueres helped rescue the climate talks after a tumultuous 2009 summit in Copenhagen and put them on a path that culminated with the Paris Agreement, the first deal asking all countries to rein in their greenhouse gas emissions.

Figueres said in the letter that U.N. Secretary-General Ban Ki-moon "will soon initiate the search" for her successor.