North Korean leader Kim Jong-un convened an emergency politburo meeting of the Workers' Party and adopted the "maximum emergency system" against coronavirus after a defector returned home from South Korea with virus symptoms, state media reported Sunday.

During the meeting held on Saturday, Kim also said he took "the preemptive measure of totally blocking Kaesong" after the "runaway" returned to the border city on July 19 after crossing the military demarcation line, three years after fleeing to the South, the Korean Central News Agency said.

"To tackle the present situation, he declared a state of emergency in the relevant area and clarified the determination of the Party Central Committee to shift from the state emergency anti-epidemic system to the maximum emergency system and issue a top-class alert," the KCNA said.

The meeting unanimously adopted the "maximum emergency system" decision, it said.

The South Korean military said chances appear high that an individual had crossed the border into the North, adding that authorities are looking into the detailed routes the person could have used.

The KCNA said that the suspected patient was put under strict quarantine as a primary step after several medical check-ups of the upper respiratory organ and blood showed "an uncertain result" that can be defined as a suspected case.

It added that "all the persons in Kaesong City who contacted that person and those who have been to the city in the last five days are being thoroughly investigated, given medical examination and put under quarantine."

"Despite the intense preventive anti-epidemic measures taken in all fields throughout the country and tight closure of all the channels for the last six months, there happened a critical situation in which the vicious virus could be said to have entered the country," Kim was quoted as saying.

Kim then instructed officials to immediately conduct follow-up organizational work to carry out the decision of the meeting and stressed the need to "thoroughly maintain tough organizational discipline."

He urged them to "overcome the present epidemic crisis by not losing the focus of thinking and action, practicing responsibility and devotion to be faithful and true to the leadership of the Party Central Committee."

The KCNA also said that the Central Military Commission of the Worker's Party will "administer a severe punishment and take necessary measures" after an investigation of the military unit responsible for the "loose guard" in the runaway case.

In late January, North Korea declared the launch of a national emergency system against the new coronavirus, shutting down its borders and tightening quarantine measures.

North Korea has yet to report a case of coronavirus but has intensified its preventive efforts across the country, calling its fight against the virus is a "political matter" that will determine the fate of the country.

On the North's Korean Central Television news broadcast, O Chun-bok, minister of public health, underscored the gravity of the situation his country faces in having to deal with a possible virus outbreak.

"In the past six months since the outbreak of infectious diseases, strong emergency measures have been taken on all fronts across the country" O said. "Despite the efforts, it appears that a dangerous crisis has occurred in which the virus may have entered our borders."

The minister also stressed the importance of wearing masks and carrying out emergency measures against the pandemic. "It's very important to foster an atmosphere in which the public holds one another accountable in terms of quarantine," O said. (Yonhap)