The Chinese embassy in South Korea has suspended issuing short-term visas for South Korean visitors, it said on Tuesday.
China has also told travel agencies in Japan that it has stopped issuing new visas for travel an apparent response to stricter measures for Chinese arrivals after their country freed up travel.
The action in Korea represents the first retaliatory move against nations imposing Covid-19 curbs on travellers from the world's second biggest economy.
The embassy will adjust the policy subject to the lifting of South Korea's “discriminatory entry restrictions” against China, it said on its official WeChat account.
The curbs come “in disregard of scientific facts and the actual epidemic situation in their own countries,"” foreign ministry spokesman Wang Wenbin told a regular briefing in Beijing, without mentioning South Korea.
“China firmly rejects this and will take reciprocal measures,” Mr Wang added. “Countries should not ... engage in political manipulation or discriminatory practices.”
The news came a day after Foreign Minister Qin Gang had expressed concern in a telephone call with his South Korean counterpart Park Jin, China's foreign ministry has said.
Mr Park told Mr Qin that South Korea's decision was made on scientific grounds, asking for both sides to work together to help stabilise the Covid-19 situations in both, the South's foreign ministry said in a statement.
The ministry added that it held discussions with Beijing after being told of its move, and would again convey its position.
"Our government's enhanced quarantine measures on travellers from China are based on scientific and objective evidence," ministry spokesperson Lim Soo-suk told a regular briefing after news of the suspension.
Chinese authorities gave notice that they had stopped issuing all tourist and business visas to Japanese nationals, said an official of a Tokyo-based agency that focuses on Chinese travel.