The United Nations has commended China's "continued strong leadership" for backing a landmark international agreement to curb climate change.

Led this year by China, the Group of 20 rich and developing nations issued a statement earlier this week following a meeting in Guangzhou to back the Paris climate accord and pledge domestic measures to bring it to force as soon as possible.

Spokesman Stephane Dujarric said Friday that U.N. Secretary-General Ban Ki-moon was "encouraged by the strong political momentum" behind the Paris Agreement, which will be signed at a ceremony at U.N. headquarters on April 22.

Full cooperation from the G20 members, in particular the United States and China — the world's largest greenhouse gas emitter — are viewed as crucial for the agreement to be effective.