"Both countries are ready to make their contribution to peace and stability in the world, in their respective regions, on various important issues", he said.
Merkel reportedly gave Li her backing for a free-trade deal between the European Union and China, but pointed out that an investment deal would be a precondition to any future trade talks.
"We will issue a joint statement on climate change that will stress that China and the European Union. will implement the agreement", a senior European Union official told reporters on Wednesday, on condition of anonymity.
Abandoning the pact would isolate the USA from a raft of worldwide allies who spent years negotiating the 2015 agreement to fight global warming and pollution by reducing carbon emissions.
However, on the foreign front, the Chinese President Xi Jinping - calling for the world to reject protectionism and promote free trade - indicated that China will take up the mantle of the leader of globalization amid an outcry over US President Donald Trump favouring protectionism.
"Despite this possible rollback of the USA administration, Europe is ready for the leadership (on climate change) and we will definitely provide it", he added.
Russian Federation joined the chorus, saying that the deal will be less effective without its key participants.
She said Beijing will uphold the outcome of the Paris Agreement and its implementation.
North Korea warns of 'bigger gift package' for US after latest test
Prior to Tuesday, the USA military had conducted 17 tests of its missile-defense system and nine were successful. This undated picture shows N Korean leader Kim Jong-Un (C) inspecting the test of a new weapon system.
But since the G7 summit, Merkel and other senior German politicians have signalled that they do not see a Trump-led United States as a reliable partner on a host of issues from free trade to climate change.
Merkel expressed appreciation for China's support for the European integration, and wished for a fruitful meeting between Li and EU leaders.
"The Americans can't just exit this climate protection treaty", EU Commission President Jean-Claude Juncker, who is to be among the officials meeting Li, said in a speech in Berlin on Wednesday.
China says it will work with the European Union to uphold the worldwide agreement on climate change even if the US pulls out.
The chancellor also warned that some sticking points between the two export giants remain, such as limited access to Chinese markets and alleged discrimination against those German firms that do operate in China. She also said it was important for non-government organisations to work in China to strengthen civil rights.
President Donald Trump will announce that the United States is withdrawing from the Paris climate change accord.
"A USA withdrawal from Paris sends a strong signal that, at the national policy level, there is little interest in Washington playing a leading role in this transition, with the impetus shifting to the US' major trading partners", he said.