Kuala Lampur, April 15 --  

SEOUL, April 15 - North Korea is showing a "very serious increase" in its ability to produce atomic weapons, the head of the UN nuclear watchdog said today on a visit to Seoul.

The diplomatically isolated north is believed to operate multiple facilities for enriching uranium, a key step in making nuclear warheads, South Korea's spy agency has said.

They include one at the Yongbyon nuclear site, which Pyongyang purportedly decommissioned after talks but later reactivated in 2021.

"In our periodic assessments, we have been able to confirm that there's a rapid increase in the operations" of the Yongbyon reactor, International Atomic Energy Agency (IAEA) chief Rafael Grossi told reporters in Seou...