President Lee Myung-Bak on Thursday said South Korea posed no security threat to North Korea even as he urged parliament to get behind reforms aimed at modernising the South's military.

In a parliamentary budget speech, Lee also called on the communist state to give up its pursuit of missile and nuclear programmes and instead focus on the needs of its impoverished population.

"There is no country in the world that threatens North Korea. We have no intention whatsoever to subvert the North's system or seek unification through absorption," he said in the speech read by Prime Minister Kim Hwang-Sik.

"Genuine threats to North Korea do not come from the outside, but from within," he said, urging Pyongyang to open its doors to the world, enhance living standards and embrace human rights.

North Korea abandoned six-nation talks on its nuclear programme in April 2009 because of what it described as US hostility. It conducted its second nuclear test the following month, sparking international condemnation and sanctions.

It also staged a failed rocket launch in April this year in what it said was an attempt to put a satellite into orbit.

The UN Security Council strongly condemned the exercise as breaching a ban on the testing of ballistic missile technology and tightened sanctions.

"North Korea's nuclear weapons and missiles should never be allowed as they impose security threats not only to the Korean peninsula but to the rest of the world," Lee said.

His speech also called for parliamentary support for a long-delayed drive to reform the military as South Korea prepares to assume wartime operational control over its armed forces from the United States in 2015.

"Now is the time for us to push strongly with defence reform aimed to build a strong and advanced army and prepare for the warfare of the future," Lee said.

The reforms envisage a change of command structures and streamlining the military into a more effective, high-tech force with rapid-response capability.

They have been one of Lee's top policy goals, especially after the alleged torpedoing of a South Korean warship by the North and the deadly shelling of a frontline island in the South in 2010.

Parliament failed to pass a defence reform bill in its last session after opposition parties argued that it could have a destabilising effect.