China called US sanctions on its entities over the Ukraine war "illegal and unilateral" and "not based on facts", in comments ahead of White House National Security Adviser Jake Sullivan's arrival in Beijing for days of high-level talks.

Last week the United States imposed sanctions on more than 400 entities and individuals for supporting Russia's war effort in Ukraine, including Chinese companies that US officials say help Moscow skirt Western sanctions and build up its military.

Washington has repeatedly warned Beijing over its support for Russia's defense industrial base and has already issued hundreds of sanctions aimed at abicurbing Moscow's lity to exploit certain technologies for military purposes.

China's special envoy for Eurasian affairs, Li Hui, who has done four rounds of shuttle diplomacy, opposed the sanctions at a briefing for diplomats in Beijing after the latest round of meetings with officials from Brazil, Indonesia, and South Africa.

"A particular country uses the crisis … to shift blame in an attempt to fabricate the so-called China responsibility theory and threatens countries that have normal economic and trade ties with Russia with illegal and unilateral sanctions," said Li.

Li did not name the United States, but China's commerce ministry said on Sunday it strongly opposed the sanctions and the foreign ministry has expressed similar opposition to previous rounds of curbs.

Last week's sanctions include measures against companies in China involved in shipping machine tools and microelectronics to Russia.

"These words and deeds are totally for their selfish interests and are not based on facts, the international community will never accept them," added Li.

China has been striving to present itself as a party that is actively looking for a solution to the conflict, despite skipping a Swiss peace conference in June.

After past rounds of talks led by Li, Beijing put forward proposals on supporting the exchange of prisoners of war, opposing the use of nuclear and biological weapons and opposing armed attacks on civilian nuclear facilities.

In a 12-point paper more than a year ago China set out general principles for ending the war, but did not get into specifics.

China and Brazil jointly called this year for Russia-Ukraine peace talks. On Tuesday, Li expressed the hope that more countries would endorse China's peace efforts.