Quarantine officials guide travelers at Incheon International Airport's Terminal 1, west of Seoul, Tuesday. (Yonhap)

South Korea's new COVID-19 cases fell below 80,000 on Wednesday amid lingering concerns over a wintertime surge, and the government has taken steps to tighten entry rules to prevent the virus inflow from China and other regions.

The country confirmed 78,575 new coronavirus infections, including 172 from overseas, bringing the total to 29,299,166, the Korea Disease Control and Prevention Agency said.

It is slightly lower from the previous day's 81,056 cases. The latest figure also marked about a 10 percent fall compared with a week earlier.

The country added 54 COVID-19 deaths, bringing the death toll to 32,355. The death rate stood at 0.11 percent.

The number of critically ill patients came to 623, up from the previous day's 620. The figure has hovered over 600 since Sunday, a level seen for the first time in about eight months.

South Korea is stepping up efforts to stem the spread of the virus amid concerns over a wintertime surge and the inflow from China, which has experienced a virus resurgence amid eased curbs.

A polymerase chain reaction test within the first day of entry became a must for entrants from China from Monday.

Starting Thursday, arrivals from China should show either a negative polymerase chain reaction or antigen test for the coronavirus before boarding flights to South Korea. They will be required to receive a polymerase chain reaction test within 48 hours before their arrival or an antigen test within 24 hours before their arrival.

Starting Saturday, travelers from Hong Kong and Macao will also be required to present a negative pre-entry virus test, the KDCA said, adding that it will review imposing additional restrictions if necessary.

Of the 172 imported cases reported Wednesday, 131 were from China, and 19 were from other Asian nations, the KDCA said.

South Korea is watching the developments regarding the new omicron subvariant of XBB 1.5, which has been spreading rapidly around the world recently. Experts said the subvariant could be more infectious and resistant to immune response.

The KDCA has said the country first found a XBB 1.5 case on Dec. 8, and a total of 13 cases have been detected so far, including seven from overseas. (Yonhap)