UN Secretary-General Ban Ki-moon on Thursday commended a joint China-U.S. presidential statement that the world’s two major greenhouse gas emitters will sign the ambitious Paris climate agreement in April.

The two countries will sign the Paris Agreement on April 22, months after the historic pact on climate change was adopted in December during the 21st session of the Conference of the Parties (COP21) in France, the statement said earlier on Thursday.

Ban also welcomed the announcement that both countries will take their respective domestic steps to join the agreement at an early date this year, said a statement released by Ban’s spokesperson