WASHINGTON — A senior US official said Monday key nations were united in watching North Korea as an investigation proceeds on whether it was involved in the sinking of a South Korean ship.

Deputy Secretary of State James Steinberg reiterated that any resumption of six-nation talks on ending North Korea's nuclear program would have to wait for the outcome of the probe on the vessel.

Speaking at the Brookings Institution, Steinberg said the United States was "engaged in an intensive discussion" with all key players about how to proceed over the sinking of the Cheonan.

Steinberg said he hoped that China, North Korea's main ally, had pressed leader Kim Jong-Il on the sinking of the Cheonan corvette when he visited Beijing this month.

"We very much hope that during the recent visit of Kim Jong-Il to China that they had an opportunity to share with him their concerns about North Korea's behavior and to make clear that we are watching very closely to see how events unfold in connection with the Cheonan," Steinberg said.

"We are determined to pursue this thoroughly and to follow the facts where they may point and this in turn will have an impact on how we proceed" on dealing with North Korea's nuclear program, he said.

Forty-six people died when the 1,200-tonne Cheonan was split in two near the tense Yellow Sea border with North Korea on March 26, possibly by a torpedo. Suspicion has fallen on the North.

On his visit to China, Kim was said to have agreed to a resumption on long-stalled six-nation talks on ending the North's nuclear program.

But South Korea and the United States quickly said any nuclear talks would have to wait for the outcome of the investigation into the Cheonan's sinking.

Copyright © 2010 AFP. All rights reserved