China reaffirmed its support on Thursday for peace efforts in Ukraine and said relevant parties should avoid "irresponsible remarks," in an apparent jab at President Volodymyr Zelenskyy's comment about Chinese citizens fighting there for Russia.

Zelenskyy said on Wednesday that Ukrainian intelligence had information about 155 Chinese citizens fighting in Ukraine. He was speaking after the capture of two Chinese nationals in eastern Ukraine, where Russian troops have been advancing.

"I would like to reiterate that China is not the initiator of the Ukrainian crisis, nor is China a participating party. We are a firm supporter and active promoter of a peaceful settlement of the crisis," foreign ministry spokesperson Lin Jian said.

"We urge the relevant parties concerned to correctly and soberly understand the role of China and to not release irresponsible remarks," he told a regular news conference, without naming Zelenskyy or any other officials.

China, which has declared a "no-limits" partnership with Russia, has tried to position itself as an actor in attempts to negotiate an end to the war. It has refrained from criticizing Russia's 2022 full-scale invasion of Ukraine.

Zelenskyy said Russia was recruiting Chinese citizens via social media, that Chinese officials were aware of it, and that Ukraine's security service had compiled lists of names, birth dates and the Russian military units where they were assigned.

Zelenskyy also said on Wednesday that Ukraine was trying to assess whether the Chinese recruits had been receiving instructions from Beijing.

Reuters could not independently verify Zelenskyy's claims, which China dismissed on Wednesday as "groundless."

Spokesperson Lin reiterated that the Chinese government always requested its citizens to stay away from armed conflict zones, "and in particular to refrain from participating in military action on either side."

Zelenskyy decried the deployment of Chinese nationals as Russia's "second mistake" in the war, after what Ukraine and Western countries have described as the dispatch of more than 11,000 North Korean troops to Russia's Kursk region.

Russia has made no public comment on Zelenskyy's statements about Chinese fighters and has never explicitly confirmed deploying North Korean troops in its Kursk region.