South Korea's health authorities announced Monday that Moderna Inc. will be providing less than half of the 8.5 million doses of its coronavirus vaccine to the country originally slated for August.

The U.S. pharmaceutical firm said there were some problems in its labs related to vaccine production that would affect global supply, according to the Korea Disease Control and Prevention Agency.

Photo shows a vial of COVID-19 vaccine developed by Moderna Inc. (Kyodo)

Moderna "apologized for the shortage, while vowing to make its best effort to supply the promised amounts to South Korea," the KDCA said in a briefing, adding that the government immediately lodged a complaint with the company.

The health authorities plan to adjust their inoculation plans for August and September accordingly.

South Korea reported 1,492 new daily COVID-19 infections on Monday, continuing its run of four-digit cases for over a month. So far, roughly 15 percent of South Koreans have been fully vaccinated.