North Korea warned Tuesday that it would "mercilessly avenge" any breach of its territorial sovereignty by South Korea or the US during their ongoing anti-submarine drills in the Yellow Sea.

The Southwestern Front Command of the Korean People's Army said the military in the region would simultaneously start actions in accordance with operation plans ratified by the supreme command, the official news agency KCNA said.

It warned that if the two parties respond "recklessly" to the North's counteractions, prompt actions by rocket forces deployed in the southwestern sector would turn the five islands nearby into a "sea of flames." The South and the US launched a five-day joint naval military drill on Monday.

The North said on Sunday that if Seoul truly worries about the future of the Kaesong industrial zone, it should stop all its hostile policy and provocative military drills toward Pyongyang.

However, a South Korean defense ministry spokesman brushed off the warnings, saying that "as long as the combined forces and South Korean military exist, the drills will continue."

Meanwhile, in a move to ease tensions, US officials were quoted by Reuters as saying on Monday that the North has taken two Musudan missiles off launch-ready status and moved them from their position after weeks of concern that Pyongyang was poised for a test launch.

However, one of the officials said the US did not believe those missiles, which had been moved, were in a non-operational location.

The move comes as UN Secretary-General Ban Ki-moon praised the South's new president, Park Geun-hye, for her firm but measured response to the North's recent provocative actions and her determination to resolve inter-Korean differences through building trust and dialogue.

Ban, a former South Korean foreign minister, met Park during her first trip to the US since she became the South's first female president in February. The heightened tensions on the Korean Peninsula, sparked by weeks of fiery rhetoric and threats from the North, dominated the talks.

UN spokesman Martin Nesirky said Ban expressed concern about the serious food shortage in the North and appreciation for the continued willingness of the South to help address the humanitarian situation there.

Global Times - Agencies