U.S. links Cheonan probe to stance toward N.Korea

WASHINGTON (Reuters) - The outcome of a probe into the sinking of a South Korean ship in March will influence how the United States deals with North Korea, a top U.S. official said on Monday.

South Korean officials have not officially accused the North but have made little secret of their belief Pyongyang deliberately torpedoed the corvette Cheonan near their disputed border in retaliation for a naval firefight last year.

"We are determined to pursue this thoroughly and to follow the facts where they point," U.S. Deputy Secretary of State James Steinberg said of an investigation into the warship's sinking, which killed 46 South Korean sailors.

"This will, in turn, have an impact on how we proceed in dealing with the challenge of North Korea and its actions, not only in the nuclear front but in other provocative measures that it takes," he added in a speech at the Brookings Institution think tank in Washington.

According to a report by South Korea's Yonhap news agency on Friday, the team of South Korean and foreign investigators investigating the incident have concluded that a torpedo was the source of an explosion that destroyed the vessel.

North Korea has denied involvement and accused South Korean President Lee Myung-bak's government of trying to use the incident for political gains ahead of local elections in June.

North Korean leader Kim Jong-il, who visited China last week, was quoted by China's Xinhua news agency as repeating a commitment to end its nuclear arms program and his willingness to discuss returning to international disarmament talks.

Pyongyang has boycotted the six-party talks, which also involve China, South Korea, the United States, Japan and Russia, since 2008.

Steinberg said that how the United States will deal with North Korea would also depend on Pyongyang's living up to its promises to abandon its nuclear programs and on its "ending its belligerent and threatening behavior toward its neighbors."

North Korea committed in 2005 to abandon all its nuclear programs but it has since conducted two nuclear tests.

The sinking of the Cheonan, if conclusively tied to North Korea, would be an escalation that could increase the chances of a widening conflict in Asia that could cripple the export-dependent economies in the region, including Japan.

"We obviously face a very challenging situation with the sinking of the Cheonan," Steinberg said. "It really underscores the precariousness of the situation on the Korean Peninsula."

(Editing by Eric Beech)