The Paris climate deal will be less effective without its key participants, the Kremlin said on Thursday, commenting on an expected announcement by U.S. President Donald Trump on whether to keep Washington in the global pact to fight climate change.

A source close to the matter has said Trump, with whom Russia wants better ties, is preparing to pull out of the accord.

President (Vladimir) Putin signed this convention in Paris. Russia attaches great significance to it,” Kremlin spokesman Dmitry Peskov told a conference call with reporters.

“At the same time, it goes without saying that the effectiveness of this convention is likely to be reduced without its key participants.”

Meanwhile, Chinese Premier Li Keqiang said in Berlin on Thursday that China will stick to its commitments on climate change as set out in the Paris Agreement, hours before Trump announces whether the United States will withdraw from the deal.

“China will stand by its responsibilities on climate change,” Li told reporters in Berlin, according to a German translation, adding it was standing by its international responsibilities and also setting national targets.

Li made the comments at a joint news conference with German Chancellor Angela Merkel, who welcomed his pledge.