US Defense Secretary Leon Panetta has promised to keep a "nuclear umbrella" over South Korea to deter threats from Pyongyang. He is in South Korea for a three-day visit after visiting Indonesia and Japan.

In an article in the English version of the Chosun Ilbo daily, the Pentagon chief reaffirmed the US's commitment to defend the South. "Working together, our militaries will continue to deter North Korean aggression, and stand prepared to defeat the North should it ever force war upon us," Panetta wrote.

He also added that the US and South Korea were developing capabilities to address the North's ballistic missile threats and strengthening operational planning.

'Positive and generally constructive'

Panetta's visit to South Korea comes just after talks between US and North Korean officials in Geneva were described as "very positive and generally constructive" by chief US envoy Stephen Bosworth. However, he also said that not all differences could be overcome rapidly.

Pyongyang has repeatedly said it will return to six-party disarmament negotiations only if there are no preconditions. However, Washington wants the North to show it is sincere about wanting to disarm by shutting down a uranium enrichment plant.

Later on Wednesday, Panetta visited US troops at the Yongsan US army base and told them that tighter Pentagon budgets would result in force reductions but not in a loss of benefits such as retirement pay for those now in uniform.

US forces have been based in South Korea since the end of the 1950-53 Korean War and some 28,500 are currently stationed there.

On Thursday, the US defense secretary is due to meet top South Korean officials, including President Lee Myung-bak.

Author: Anne Thomas (Reuters, dpa, AFP)
Editor: Manasi Gopalakrishnan