China defends visa retaliation over COVID

Chinese state media has defended retaliatory measures against South Korea and Japan over their COVID-19 travel curbs as "reasonable", while Chinese tourists decry Seoul's "insulting" treatment on social media.

China re-opened its borders on Sunday after three years of isolation under the world's strictest regime of COVID restrictions, which Beijing abruptly began dismantling in early December after historic protests.

With the virus spreading unchecked among China's 1.4 billion people after the policy U-turn, some foreign governments have raised concerns about the scale and impact of the outbreak, with the World Health Organisation saying deaths are under-reported.

In a first, China's health authorities, which have been reporting five or fewer deaths a day in the past month - numbers that are inconsistent with the long queues seen at funeral homes - did not report COVID fatalities data on Tuesday.

China's Centre for Disease Control and Prevention and the country's National Health Commission did not immediately respond to requests for comment.

More than a dozen countries including the United States, Australia and some European Union members have imposed requirements for pre-departure negative test results from visitors from China.

South Korea and Japan have also limited flights and require tests on arrival, with passengers showing up as positive sent to quarantine.

In response, Chinese embassies in Seoul and Tokyo said on Tuesday they had suspended issuing short-term visas for travellers to China, with the foreign ministry slamming the testing requirements as "discriminatory".

China requires negative test results from visitors from all countries.

State-run nationalist tabloid Global Times defended Beijing's retaliation as a "direct and reasonable response to protect its own legitimate interests, particularly after some countries are continuing hyping up China's epidemic situation by putting travel restrictions for political manipulation".

South Korean foreign minister Park Jin has said the country's decision was based on scientific evidence, while Japan lodged a protest with China over its suspension of visas for Japanese citizens.

Chinese social media anger mainly targeted South Korea, whose new border measures are the strictest.

Flights can only land at Incheon International Airport and those who test positive on arrival are sent to a designated quarantine facility for seven days at their own cost.

Videos circulating online showed special lanes co-ordinated by soldiers in uniform for arrivals from China at the airport, with travellers given yellow lanyards with QR codes for processing test results.

One user of China's Twitter-like Weibo said singling out Chinese travellers was "insulting" and akin to "people treated as criminals and paraded on the streets".

Global Times said South Korea's measures made Chinese people suspicious Seoul was putting up a "political show".

"Seoul should not be surprised by China's countermeasures," it said in the article, which also criticised "very poor" quarantine conditions.

The tensions hurt share prices of South Korean companies with exposure to China, including cosmetics makers LG H&H and Amorepacific.

Annual spending by Chinese tourists abroad reached $US250 billion ($A361 billion) before the pandemic, with South Korea and Japan among the top shopping destinations.