At least 44.22 million people, or 86.2 percent of the population, are considered fully vaccinated. Sunday's 54,619 new cases took the tally of infections to 1,405,246, the Korea Disease Control and Prevention Agency (KDCA).
The death toll rose by 21 to 7,102.
As the Omicron variant of coronavirus became dominant last month, the government began to restrict free polymerase chain reaction (PCR) tests to those in high risk groups.
Others must first take rapid antigen tests using kits sold at stores, or offered free by public health centres.
On Sunday, authorities imposed a three-week rationing period on test kits for home use, by limiting online sales as well as pharmacy purchases to five to a person at a single location.
However, the total number available to buy will not be curbed, authorities said, as they believe stocks to be adequate in the absence of major hoarding.
Kwon said about 30 million additional self-test kits will be supplied nationwide this month to dispel concerns about shortages. The government has said it plans to provide 190 million self-test kits for March, more than twice the supply in February.