South Korea’s military said it will strike back at North Korea and target its top leadership if Pyongyang launches a threatened attack in response to what it says are “hostile” drills between US and South Korean forces.

One of North Korea’s top generals, in a rare appearance on state TV on Tuesday, said Pyongyang had torn up its armistice deal with Washington and threatened military action against the US and South Korea if the drills continued.

The military exercises began on March 1 and run until April 30.

North Korea is gearing up to expand its own military drills and may be preparing to test-fire short-to-medium-range missiles by banning flights and sailing off its coast, South Korea’s Yonhap news agency said, quoting South Korean government sources. “The North’s military... is preparing large-scale combined military exercises so it may have blocked off the areas for nautical firing or fighter jet firing exercises,” Yonhap quoted a South Korean government source as saying.

“But the firing of missiles cannot be ruled out.”

The South’s Defence Ministry and office of the Joint Chiefs of Staff could not confirm that report, but South Korean officials have said the North is conducting military exercises that appear to be larger in scale than in past years.

Tensions have ratcheted higher across the Korean peninsula since the North, under youthful leader Kim Jong-un who took office just over a year ago after the death of his father, launched a long-range rocket in December. He followed this with a third nuclear test on February 12, triggering the prospect of more UN sanctions that are being formally announced today after the United States and China, the North’s one major diplomatic ally, struck a deal to punish Pyongyang.

At the same time, North Korea has stepped up its military threats against South Korea and the United States, prompting the terse warning from Seoul yesterday that it would not stand idly by if its territory was attacked.

“We have preparations for strong and decisive punishment against the source of the aggression and its support forces but also the commanding element,” Major General Kim Yong-hyun of the South Korean said.