South Korea's daily new coronavirus cases fell back below 2,000 on Thursday, but the peak of the current wave of the pandemic has not yet come amid calls for tougher measures to bring virus infections under control and slow vaccinations.

The country added 1,987 COVID-19 cases, including 1,947 local infections, raising the total caseload to 218,192, according to the Korea Disease Control and Prevention Agency (KDCA).

The daily caseload was down 236 from 2,223 the previous day, the largest since the outbreak of the pandemic here in late January last year. The country added three more deaths from COVID-19, raising the death toll to 2,138.

The daily caseload has stayed above 1,000 for 37 days.

Despite the toughest social distancing measures having been in place for more than a month, the fourth wave of the pandemic has not showed signs of letup, prodding health authorities to consider more enhanced virus curbs.

The authorities cited increased travel during the summer season and the fast spread of the highly transmissible delta variant as the reason for the recent surge.

The greater Seoul area, the epicenter of the latest wave of the outbreak, has been under the Level 4 distancing measures, the highest in the country's four-tier system, since July with most other areas being under Level 3.

Amid the spiking cases, the country's vaccination rate has been slow, mainly due to problems in securing vaccines on time.

Since the country launched its vaccination program in late February, a total of 21.81 million people, or 42.5 percent of the country's 51.34 million population, have received their first shots of COVID-19 vaccines.

Around 16 percent, or 8.22 million people, have been fully vaccinated, according to KDCA data.

The country aims to administer a single vaccination shot to 36 million people, or 70 percent of its population, by September with hopes of reaching herd immunity in November.

Advance reservations for vaccinations for people aged 18 to 49, estimated at some 16 million, started on Monday.

Of the locally transmitted cases, 522 were reported in Seoul, with the surrounding Gyeonggi Province adding 570, and the western port city of Incheon confirming 109 more new cases.

The southeastern port city of Busan posted 128 new cases, while neighboring South Gyeongsang Province reported 108 more infections.

There were 40 cases from overseas arrivals.

The total number of people released from quarantine after making full recoveries was 190,535, up 1,029 from a day earlier. (Yonhap)