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 television today, 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 1st and run until April 30th.
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 previous 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 12th, triggering the prospect of more UN sanctions that are due to be formally announced tomorrow 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 today that it would not stand idly by if its territory was attacked.
"We have all preparations in place for strong and decisive punishment, not only against the source of the aggression and its support forces but also the commanding element," major general Kim Yong-hyun of the South Korean army told a news conference in one of the clearest threats Seoul has made.
North Korea's bellicose rhetoric rarely goes beyond just that, although in 2010 it was widely accused of sinking a South Korean naval vessel, killing 46 sailors, and in the same year shelled a South Korean island, killing two civilians.
Stung by criticism it took too long to respond to the island shelling, South Korea's military has relaxed its rules, allowing commanders on the ground to respond to aggression instead of needing permission from top military brass.
South Korea's new President Park Geun-hye had pledged to engage the North if it dropped its nuclear plans but now faces the prospect of a hostile challenge early in her five-year term.
Japan's Kyodo news agency said some people in the North's capital, Pyongyang, were covering up buses and other larger vehicles with camouflage nets in what it said was a possible preparation for war.
Reuters