The United States has again refuted North Korea’s claim that it was not responsible for the sinking of the Cheonan naval ship.

State Department spokesman Philip Crowley told reporters Friday that if North Korea wants to investigate the sinking of the Cheonan, as it indicated it might, it might start by taking an inventory of its torpedoes. With his statement, Crowley refused for a second time Pyongyang’s wishes to send its inspectors to South Korea for its own probe on the Cheonan’s sinking.

Crowley added that South Korea and other countries that conducted the investigation into the Cheonan’s sinking will bring the matter to the U.N. Security Council in a formal meeting on Monday.

The military and civic joint probe team that investigated the sinking of the Cheonan is scheduled to brief members of the Security Council about their findings on Monday at 3 p.m. local time at the U.N. Headquarters in New York.