South Korea on Sunday condemned North Korea's latest short-range missile launches as "provocative" and again urged it to hold talks about a suspended jointly-run industrial park.

The North Saturday launched three short-range guided missiles off its east coast, apparently as part of a military drill, at a time when cross-border relations remain icy after months of simmering tension.

The South and US forces had earlier been on heightened alert for any test of medium-range Musudan missiles by the North, which for weeks made threats of nuclear or conventional attacks on Seoul and Washington.

The latest launch only involves short-range missiles. But it poses threats to the region and should be "stopped immediately", said the Seoul ministry that handles cross-border affairs.

"We find it deplorable that the North does not stop provocative actions such as the launch of guided missiles yesterday," said unification ministry spokesman Kim Hyung-Seok.

"We call on the North to take responsible actions for our sake and for the sake of the international community."

The US State Department Saturday urged the North to exercise restraint, without specifically commenting on the launches.

Tensions had shown signs of abating after a US defence official said early in May that two Musudan missiles had been moved from their launch site.

Spokesman Kim also urged the North to respond to the South's repeated calls for talks about the jointly-run Kaesong industrial complex, where work has been suspended because of the political standoff.

Kaesong, established just north of the border in 2004 as a rare symbol of inter-Korean cooperation, was the most high-profile casualty of two months of elevated military tensions that followed the North's atomic test in February.

The North barred South Korean access to the zone and pulled out its own 53,000 workers early last month. Seoul withdrew the last of its nationals early this month.

When the South Koreans left, they loaded up cars with bundles of products, but were still forced to leave many stocks behind.

The North last week rejected the South's call for talks on removing goods from the complex, calling it "a crafty ploy" to deflect blame for the suspension of operations.

"It is very regrettable that the North denigrates our offer for talks... and shifts blame for the suspension of the Kaesong complex to us," Kim said, urging Pyongyang to come forward for talks as soon as possible.