By Jung Sung-ki
Staff reporter
South Korea plans to send a letter to the president of the U.N. Security Council (UNSC) soon regarding the sinking of the South Korean frigate Cheonan near the sea border with North Korea on March 26, a report said Monday.
This will be the initial step in referring the naval incident to the UNSC, Yonhap News Agency said, adding the government believes North Korea was behind the sinking that claimed the lives of 46 sailors.
The letter will be sent after an announcement ― due around Thursday ― of the results of an investigation into the cause of the tragedy, according to the report.
Kim Young-sun, a spokesman for the Ministry of Foreign Affairs and Trade, declined to confirm the move, saying detailed countermeasures would be made public after the final announcement.
Kim said the government plans to brief the results to related countries beforehand.
"We plan to explain the results of the investigation to related countries before a final announcement, but consultations are under way over which nations it will be and when the briefings will be made," Kim told reporters.
Separately, Vice Defense Minister Chang Soo-man invited ambassadors of the United States, Britain, Australia and Sweden to the ministry and thanked them for their cooperation in the Cheonan investigation, a ministry spokesman said.
Experts from the four countries have been participating in the multinational team looking into the disaster.
The ministry will also invite military attaches of foreign embassies here to brief them on the outcome, the spokesman said.
Diplomatic sources said the government will outline a set of measures to respond to North Korea after the May 20 announcement.
The measures will include referring the case to the UNSC, strengthening the ROK-U.S. combined defense readiness, a review of inter-Korean economic projects, reviving radio propaganda near the border and including the North on a blacklist of countries on which international financial sanctions are imposed, the sources said.
Chinese Ambassador to South Korea Zhang Xinsheng called for "verifiable and irreversible evidence" regarding the investigation of the incident, according to Rep. Choi Moon-soon of the main opposition Democratic Party (DP).
During a meeting with DP Chairman Chung Sye-kyun, Zhang was quoted as saying that there were still many outstanding issues that investigators needed to look closely at regarding the cause of the maritime disaster.
No concrete evidence has been found so far, Zhang said.
China's stance could play a pivotal role in resolving the Cheonan row, given it is North Korea's closet ally and is one of the five veto-wielding permanent members of the UNSC.

정부는 월요일 북한과의 서해 접경에서 지난 3월 26일 침몰한 천안함 관련 유엔안보리 의장에게 서한을 보낼 예정이라 국내 뉴스 보도가 밝혔다.
연합뉴스는 이번 서한은 천안함 사태를 안보리에 언급하는 첫 단계가 될 것이며, 정부는 46명의 승조원의 목숨을 앗아간 이번 사태의 배후가 북한이라고 믿고 있다고 보도했다.
보도에 따르면, 정부는 안보리에 보낼 서한을 목요일 경 예정된 조사경위가 발표된 후에 보낼 것이라고 밝혔다.
김영선 외교통상부 대변인은 자세한 대응책은 최종 조사 발표 후 공개할 것이라며 보도 내용을 확인해주길 거부했다.