South Korea recognises the vaccination status of Korean citizens who were vaccinated overseas but not foreigners, unless they entered the country under a quarantine exemption.

Some foreign residents, particularly from Europe and the United States, were vaccinated earlier in the year when South Korea had not yet made vaccines available and were not eligible for the quarantine exemptions that were extended to certain people in business, education or for humanitarian reasons.

It is unclear how many people are affected but the problem has caught the attention of several foreign embassies, which have been lobbying unsuccessfully for weeks for a change.

"We continue to argue for urgent review of the guidance in order to ensure equitable treatment of foreign and Korean nationals vaccinated overseas," Stephen Burns, a spokesman for the British embassy in Seoul, told Reuters.

The Australian Embassy is in ongoing contact with the South Korean government on this matter and continues to advocate for a change to their policy, ambassador Catherine Raper said in a post on Twitter on Monday.

The Korea Disease Control and Prevention Agency says the policy affects a small number of people and is necessary given rising COVID-19 cases.

"A cautious approach is required at this time with locally and globally confirmed cases of the Omicron variant and the possibility of further community spread," a spokesperson said, adding that officials will review the rules depending on the domestic outbreak situation.

The KDCA reported 4325 new COVID-19 infections on Monday, for a total of 477,358 since the pandemic began, with 3893 deaths overall. The country has detected 24 cases of the new Omicron variant.

In response to growing daily cases, South Korea has put on hold previous efforts to "live with COVID-19", instead imposing new vaccine pass requirements and ending quarantine exemptions for all travellers arriving from overseas.

The problem for foreigners with unregistered vaccines stands to become more acute as previous rules that required a government vaccine pass or negative COVID-19 test for entry to gyms, saunas, and bars have now been expanded to include cafes, restaurants, cinemas and other public spaces.

Unvaccinated individuals or people without proof of vaccination can still dine in restaurants, but only if they sit alone.

"An example of how South Korea isn't quite a truly global, international country yet," tweeted Jean Lee, an analyst on Korea affairs at US-based Wilson Centre.

In March, authorities in several major cities including Seoul sparked an uproar by ordering all foreign workers be tested for coronavirus.

Some of those measures were dropped after complaints by embassies and a human rights probe.

Australian Associated Press