In a phone call with Moon late Thursday, Xi said he strongly endorses progress in easing tensions on the peninsula, South Korean television network MBC reported.
"We should set out together in improving South-North relations and in denuclearizing the Korean peninsula," Xi said, according to a statement from Seoul's presidential Blue House.
Moon and Xi agreed to find a peaceful solution to the North Korea nuclear issue through strengthening of communication and cooperation between Seoul and Beijing.
Moon also invited the Chinese leader to attend the closing ceremony of the 2018 Pyeongchang Winter Olympics.
Xi did not give a definitive answer, according to the report.
The phone call comes a day after U.S. President Donald Trump told Moon he is open to talks between Washington and Pyongyang.
Trump had also assured Moon there would be no military activity during the period of inter-Korea dialogue.
The United States is expected to send Vice President Mike Pence to attend the Winter Games as part of the official delegation, and there is speculation Ivanka Trump might join him at one of the ceremonies.
There is less certainty whether Japanese Prime Minister Shinzo Abe is to attend the ceremonies for the Games.
Tokyo's Chief Cabinet Secretary Yoshihide Suga said Thursday the government has not reached a final decision on whether to attend the Winter Olympics, South Korean news service EDaily reported.
"Korea has invited Prime Minister Abe to the Pyeongchang Winter Olympics, but we will be reviewing the decision after looking into the parliamentary schedule," Suga said.
Conservative paper Sankei Shimbun reported Wednesday calls for a Japanese apology for Korean "comfort women" forced to serve in wartime brothels has solidified Abe's decision to not attend the games.