The Obama administration will likely push for new sanctions against North Korea and step up naval maneuvers with its ally South Korea over the sinking of a Seoul warship, analysts said Thursday.

With an international probe concluding North Korea torpedoed the Cheonan on March 26, Washington must throw full support behind Seoul, yet stop short of actions that could trigger a new war on the Korean peninsula, they warned.

US Secretary of State Hillary Clinton is expected to weigh responses to Kim Jong-Il's reclusive Stalinist regime during her week-long tour of South Korea, China and Japan, where she arrives on Friday.

"Going to the UN Security Council and pushing for a tougher resolution is a must, just to demonstrate international solidarity in the wake of the conclusions of the investigation," Center for Strategic and International Studies analyst Nicholas Szechenyi told AFP.

It remains unclear whether North Korea's closest ally China would go along with another round of sanctions.

"China is the wild card," Szechenyi said.

But after North Korea last year test-fired a long-range rocket and staged a second nuclear test, China surprised many analysts when it backed a tough sanctions regime that allowed for the interdiction of suspect North Korean ships.

President Barack Obama's administration will probably suspend the six-party nuclear disarmament talks that have appeared moribund for nearly two years anyway, Szechenyi ventured.

He said the Obama team could place North Korea back on the list of state supporters of terror, after the previous George W. Bush administration removed it from the list in a failed bid to boost the nuclear talks.

The move would trigger further unilateral US sanctions, adding pressure on the decrepit North Korean economy.

State Department spokesman Philip Crowley would not rule out Washington's putting Pyongyang back on the blacklist or taking any other actions, but he said the United States will be guided by what South Korea decides.

Analysts also believe the Obama administration, which has taken a relatively tough line on North Korea from the outset, could delay agreed plans to transfer wartime operational control to South Korea in 2012.

In another military move, the administration could step up joint naval exercises the United States regularly holds with South Korea. The last round took place in March.

"In the wake of this brazen attack, it's important to remind North Korea and the region of the US commitment to deterrence," Szechenyi explained.

Nicole Finnemann, an analyst with the Korea Economic Institute, said it makes sense for Washington to both step up naval exercises with Seoul and delay transferring wartime operational control to the South Korean military over several months, rather than abruptly.

Policy planners are said to be receptive to possibly expanding exercises along the Korean peninsula's west coast, near the disputed maritime border, rather than along the east coast, where they have taken place in the past.

Such exercises could train forces in removing both mines and torpedos, as well as involve more regional powers, Finnemann said.

Sarah McDowall of economic forecasting firm IHS Global Insight agreed "there is likely to be a renewed show of US-South Korean capabilities in the region," in the form of joint naval exercises in the Yellow Sea where the warship sank.

Bruce W. Bennett, a senior defense analyst at the Rand Corporation who was visiting Seoul, said there were fears in South Korea that Kim was bent on escalating the conflict to ensure the military is behind his fragile regime.

"If that's the case, then anything really hostile that we do is likely going to generate more military support for him and against us," Bennett told AFP.

He said he fears the ailing Kim may pursue a limited, covert-style war that would help him ensure the North Korean military backs the eventual handover of rule to his youngest son Kim Jong-Un, who is 26.

The United States stations some 28,500 troops to bolster South Korea's 655,000-strong armed forces against the North's military of 1.2 million troops.

It also guarantees a "nuclear umbrella" over its long-time ally in case of a nuclear attack.