BEIJING - North Korea has conducted a firepower demonstration of various weapons systems including drones, cruise missiles and multiple rocket launchers at an exhibition on unmanned aerial technology, with leader Kim Jong Un calling for a rapid expansion of drone technology, state-run media said Friday.

At Thursday's event, Kim said it is "an indispensable option" to aim to seize "absolute superiority" in drone technology amid the "ever-changing patterns of modern warfare," the official Korean Central News Agency said.

"Strength precisely means peace and peace is guaranteed only by strength," he said, calling for progress in the development of unmanned aeronautical technology and artificial intelligence as North Korea has made "new leaps forward in upgrading conventional weapons" in addition to acquiring nuclear weapons, KCNA reported.

Images released by the agency showed the multiple launchers firing at least 15 rockets, which are regarded by Japan, the United States and South Korea as ballistic missiles.

On Thursday, the South Korean military detected the launch of around 10 short-range ballistic missiles toward the Sea of Japan from an area around Wonsan on North Korea's eastern coast.

Kim mentioned "important state measures" for rapidly developing unmanned aeronautical technology but did not elaborate. He attended the exhibition with his wife and daughter.

Meanwhile, the North Korean Defense Ministry condemned the U.S.-South Korea Freedom Flag air exercise that began Monday at Kunsan Air Base in western South Korea, saying in a statement carried by KCNA that it has "unprecedentedly escalated the military tension" on the Korean Peninsula.

"There is no limit for the DPRK's option to maintain a strong deterrent posture capable of effectively coping with all threats posed by the military moves of the U.S. and its vassal forces," the statement on Friday said, referring to the country's official name, the Democratic People's Republic of Korea.

The joint exercise will run through Nov. 6. Tensions between the two Koreas have been escalating since a land mine blast in the border area in late September that injured three South Korean soldiers.

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