South Korea says it will take the case of its sunken naval vessel to the UN Security Council.
The presidential office said on May 23 that President Lee Myung-bak will make this clear in a speech about the incident with North Korea on May 24.
Last week, Seoul released the findings of a report which concluded that a North Korean submarine had fired a torpedo that sank the corvette "Cheonan," killing 46 sailors.
The North has denied the accusation. U.S. Secretary of State Hillary Clinton is to raise the ship case in her coming talks with Chinese leaders in Beijing.