Li Keqiang, the Chinese prime minister, said on Thursday that his country would continue to work with the European Union and other countries to uphold the deal.
Speaking after bilateral talks with German Chancellor Angela Merkel in Berlin, Li said it was "also in our interest ... to work step by step towards sustainable development" and environmental protection together with the international community.
"China will stand by its responsibilities on climate change," he told reporters, according to a German translation.
Merkel referred to Li's assurance as "very encouraging".
"China has become a more important and strategic partner," Merkel said in the news conference.
Their comments come after reports that the US will withdraw from the landmark 2015 international agreement to limit greenhouse gas emissions - US President Donald Trump is expected to make an announcement later on Thursday.
China is the top emitter of carbon dioxide, and the US is second. Both were key to the 2015 Paris Agreement, which was signed by 195 countries and aims to limit the increase in global temperature to two degrees Celsius above pre-industrial levels by 2100.
The White House signalled that Trump was likely to decide on exiting the global pact — fulfilling one of his main campaign pledges - though top aides were divided.
If the US decides to pull out, it will join Syria and Nicaragua as the only two countries not participating in the accord.
The European Commission President Jean-Claude Juncker said it was the "duty of Europe" to stand up to Trump if he decided to pull his country out of the historic accord.
The EU and China are expected to "spell out" how they plan to meet their agreed commitments to fight global warming at talks in Brussels on Friday.
A major Chinese delegation is due to arrive in Brussels late on Thursday following the talks in Berlin.
"The EU and China are joining forces to forge ahead on the implementation of the Paris Agreement and accelerate the global transition to clean energy," Miguel Arias Canete, the EU climate commissioner, said about the upcoming EU-China summit.