Local health authorities are warning it is a matter of time before the more transmissible Delta variant of COVID-19 spreads across the Seoul metro area. 

Kwon Jun-wook, deputy chief of the Korea Disease Control and Prevention Agency(KDCA), issued the forecast in a media briefing on Friday. 

He said the Delta variant is assessed to be one-point-five times more infectious than the Alpha variant, also known as the UK strain. Kwon expects the Delta variant to expand its footprint as the virus' reproduction rate for the capital region sits at 1.24 and at 1.2 for the country overall in the past week. He characterized them as both "very high levels." 

Regarding the observed increase in imported infections, Kwon said many have been overseas Koreans returning from Indonesia, currently grappling with a spike in COVID-19 infections. He said authorities are strengthening regulations on arrivals from the Southeast Asian country, adding that swift responses would be made for other vulnerable nations as well.