President Moon Jae-in instructed aides Tuesday to make greater efforts to prevent the spread of the omicron variant, urging more people to get booster shots as the nation is struggling with a spike in COVID-19 deaths and infections.

"We are facing a very grave situation as the numbers of confirmed patients, critically ill patients and deaths are on the rise, coupled with the omicron variant," Moon told a Cabinet meeting.

Amid growing alarm over omicron, which is potentially more contagious than the delta variant, Moon called for vaccinated people to get their booster shots.

"Recent breakthrough cases and the spread of omicron strongly show that a third shot is important," Moon said.

So far, 36 omicron cases have been confirmed, including three reported in Seoul earlier in the day.

With daily infections hovering around 5,000 and the number of serious COVID-19 patients continuing to hit new highs, the authorities earlier decided to impose stricter social distancing rules, adjusting the pace of the the "living with COVID-19" campaign.

From Monday till Jan. 2, the maximum number of people at private gatherings has been reduced to six in the greater Seoul area and eight in other areas, from the current 10 and 12.

Visitors to high-risk businesses, including saunas, pubs and gyms, have to show proof that they have been vaccinated or have a negative coronavirus test result.

Last week, the National Assembly passed the 2022 government budget, a record high amount of 607.7 trillion won (US$516.3 billion), to cope with the economic fallout of the COVID-19 pandemic and other expenses.

Moon said next year's budget is expected to bolster spending on containment and hospital systems and provide more support for self-employed people hit by the pandemic.

Faced with growing economic uncertainties amid the worsening COVID-19 situation around the world, Moon also called for his aides to set up contingency measures on the nation's financial markets. (Yonhap)