US President Barack Obama listens to a question during a visit to Pittsburgh June 17, 2014. During the event, Obama said that Ahmed Abu Khatallah, the suspected ringleader of the 2012 attack on the U.S. diplomatic compound in Benghazi, Libya, was being transported to the United States after his capture on Sunday. Picture: Kevin Lamarque

New York - The United States told the United Nations Security Council that a suspected ringleader of the deadly 2012 attack on its diplomatic compound in Benghazi, Libya had been planning to target more Americans and that justified his capture.

In a letter obtained by Reuters on Wednesday, the US ambassador to the UN, Samantha Power, notified the council of the capture on Sunday of Ahmed Abu Khatallah by US special forces in Libya after an investigation identified him as a key figure in the 2012 attack that killed four Americans.

“The investigation also determined that he continued to plan further armed attacks against US persons,” Power wrote in the letter dated Tuesday.

“The measures we have taken to capture Abu Khatallah in Libya were therefore necessary to prevent such armed attacks, and were taken in accordance with the United States' inherent right of self-defence,” she wrote.

Power said the United States was reporting the capture of Khatallah to the Security Council under Article 51 of the UN Charter, which requires that the body be notified immediately of measures taken by states in self-defence against armed attack.

The brief letter also said Khatallah would be presented to US Federal Court for criminal prosecution. - Reuters