South Korea's new coronavirus cases fell below 7,000 on Friday for the second day in a row on the back of antivirus restrictions, but critical cases surged to a record high again.

The country added 6,233 more COVID-19 cases, including 6,163 local infections, bringing the cumulative total to 596,209, the Korea Disease Control and Prevention Agency (KDCA) said.

Friday's tally is down from 6,918 on Thursday and sharply down from 7,434 reported on Dec. 17.

The number of critically ill patients, however, came to a fresh high of 1,084, the KDCA said, breaking the previous record high of 1,083 tallied Thursday.

The country added 56 more deaths from COVID-19, bringing the total to 5,071. The fatality rate stood at 0.85 percent, unchanged from a day earlier.

The country reported 16 new omicron variant cases, bringing the total to 262, the authorities said.

On Saturday, the government reimposed a set of revised virus restrictions across the country, which will remain in effect until Jan. 2 to stem the spread of the virus.

It marks a reversal of the government's "living with COVID-19" scheme that began early last month, with an aim to return to normalcy by relaxing virus restrictions in phased steps.

Under the new measures, the maximum size of private gatherings is limited to four people nationwide, from the previous limit of six in the capital area and eight elsewhere.

A 9 p.m. or 10 p.m. curfew is applied to businesses as well, depending on their type of service.

The authorities said the outbreak has entered a downward trend, adding that they will decide whether to extend the restrictions after reviewing next week's daily tallies.

Of the locally transmitted cases, Seoul reported 2,324 infections and Gyeonggi Province that surrounds the capital logged 1,647 cases.

The KDCA said 80 cases came from overseas, raising the caseload to 16,670.

As of Friday, 85.5 percent of the country's 52 million people had received their first shots of COVID-19 vaccines, and 82.3 percent had been fully vaccinated, while 27.9 percent had gotten booster shots, the KDCA said.

Earlier, Prime Minister Kim Boo-kyum said the government is in the final stage of signing a contract with U.S. drug giant Pfizer Inc. to get its oral drug for COVID-19, Paxlovid.

Kim said the government has been discussing a purchasing deal with Pfizer for 300,000 people that is much more than the previously announced plan of 70,000 people. Details will soon be announced.

Kim's remarks came after the U.S. Food and Drug Administration granted an Emergency Use Authorization approval of Paxlovid.

The Ministry of Food and Drug Safety's emergency authorization of Paxlovid is also expected to come out next week.

Health authorities also said they are in close talks with Pfizer to make sure South Korea can import the oral pill by end-January.

The drug candidate is a protease inhibitor antiviral therapy that is specifically designed to be administered orally so that it can be prescribed at the first sign of infection or at first awareness of an exposure.

Pfizer said its trial results showed Paxlovid reduces by 89 percent the risk of hospitalization or death in patients at high risk of severe illness within three days of the onset of COVID-19 symptoms.

The KDCA also said a homegrown polymerase chain reaction (PCR) test was developed that can detect the omicron variant within three to four hours of diagnosis.

The new PCR test, co-developed by the private sector, will be used by health authorities starting next Thursday, the authorities said. (Yonhap)