South Korea is planning to add air-launched cruise missiles capable of destroying high value targets in North Korea to its arsenal, reports and officials said Wednesday.

The plan is awaiting parliamentary approval, a defence ministry spokesman told AFP, adding that the air force wanted to buy some 170 missiles.

South Korea wants the air-to-surface stealth missiles as a deterrent against provocation by North Korea, the Korea Times said.

"It can be fired from Seoul and hit any targets in Pyongyang," a government source was quoted as saying.

The government has set aside some 388 billion won ($344 million) to procure precision guided missiles that can be launched from jets, the daily said.

The Joint Air-to-Surface Standoff Missile (JASSM) from US defence giant Lockheed Martin will vie with the Taurus missile produced by Germany-based Taurus Systems GmbH, it said.

Seoul hopes to assess the two missiles over their performance, price and the extent of technology transfer and to select the winner no later than September next year, it said.

JASSM, which has an operational range of 370 kilometres, is cheaper but the US Congress has yet to authorise exports of the weapon to Seoul, it said.

South Korea may push for the development of air-to-ground cruise missiles if it cannot buy them at a reasonable price and secure a guarantee of substantial technology transfer, it said.

The South has developed various missiles to counter the threat of North Korean ballistic missiles.

The North has about 600 Scud missiles capable of hitting targets in South Korea, and possibly also of reaching Japanese territory in some cases, according to South Korean military data.

There are another 200 Rodong-1 missiles which could reach Tokyo. In addition the North has three times test-launched intercontinental Taepodong missiles.