SEOUL (Reuters) – South Korea said on Sunday it would take the case of its sunken naval vessel to the UN Security Council in a bid to tighten the economic vice on impoverished North Korea after accusing it of torpedoing the ship.

The March sinking of the Cheonan corvette, killing 46 sailors, has sharply raised tensions on the Korean peninsula, rattled investors in South Korea and threatens to divide major powers in the economically powerful region.
“The president will present frameworks of measures, one about our own steps and the other about measures through international cooperation ... He will also mention a plan to bring the case to the UN Security Council,” presidential spokesman Lee Dong-kwan said.
He said President Lee Myung-bak would address the issue in a speech on Monday, scheduled for 9 p.m. ET.
In what is likely to further goad the prickly North, the spokesman said President Lee may mention North Korean leader Kim Jong-il by name in his speech.
Pyongyang, which claims innocence, is already fuming after international investigators pointed the finger of blame at a North Korean submarine and said it is ready to go to war if South Korea retaliates.
Seoul has made clear it will not launch any military strike and, because relations have almost frozen since Lee took office in 2008, has little left to punish North Korea apart from seeking more international economic sanctions.
South Korea can be sure of a sympathetic hearing from permanent UN Security Council members the United States and Britain, both of which sent officials to help the investigation into the sinking.
Much more difficult will to be to win over China, which effectively bankrolls North Korea's ruined economy and which has so far declined to be drawn on the question of blame over the sinking.
Washington, struggling to keep its own relations with China on an even keel, has called for an “international response” to the sinking. It has yet to specify what that might mean.
The issue is likely to overshadow a summit of leaders from China, Japan and South Korea later this month.
“Japan has said it will cooperate with South Korea when deciding how it will act. So I think we will consider our action accordingly,” Hidenobu Sobashima, deputy press secretary at the Foreign Ministry, told Reuters.