WASHINGTON (AP) — A U.S. official says South Korea will lay out evidence later this week that Pyongyang sank one of the South's navy ships in March, killing 46 sailors.

The official says South Korea will offer proof that it was a North Korean torpedo that slammed into the ship, sinking it near the two countries' border. U.S. officials have assisted in the investigation.

The official spoke late Tuesday on condition of anonymity ahead of the official announcement by South Korean officials.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

WASHINGTON (AP) — Secretary of State Hillary Rodham Clinton was meeting with the Obama administration's envoys to North Korea amid reports that an investigation will blame Pyongyang for the sinking of South Korean navy ship that killed 46 sailors.

Clinton was to meet privately Tuesday with the envoys, Stephen Bosworth and Sung Kim, after South Korea's Yonhap news agency reported that Seoul officials planned to release an investigation later this week into the March 26 sinking near the border with North Korea.

Yonhap said the investigators had obtained traces of explosives used in a type of North Korean torpedo.

The South Korean Defense Ministry said it couldn't confirm the report. The North has denied involvement.

South Korean President Lee Myung-bak spoke with President Barack Obama on the phone Monday and discussed the sinking.

The incident, along with concerns about North Korea's nuclear program, will dominate much of Clinton's upcoming talks with leaders in Tokyo, Beijing and Seoul, where she will wrap up an Asian trip next week.

Earlier Tuesday, Chosun Ilbo and other South Korean newspapers reported that investigators found fragments of what appeared to be Soviet- or Chinese-made torpedo near the wreck.

State Department spokesman P.J. Crowley told reporters that North Korea must "cease provocative acts, cease acts of aggression that destabilize the region" and urged the North to follow through on past commitments to abandon its nuclear programs.

The United States had pushed the North to return to stalled six-nation nuclear disarmament talks, but U.S. officials have said the findings of the ship sinking investigation will be a major factor in whether those talks resume.

The two Koreas remain technically at war because their three-year conflict ended in a truce, not a peace treaty, in 1953. South Korea has said it will take stern action against anyone responsible for the sinking.