Luis Moreno-Ocampo told reporters he informed the U.N. Security Council, which asked the court in 2005 to investigate the Darfur crisis, of his progress before requesting a court warrant on Monday to arrest President Omar al-Bashir.

"This was my last week to do it, so I did it when I had my evidence ready," said Moreno-Ocampo, noting that the court was about to take a summer recess.

He added that his responsibility is to investigate cases and he "cannot be considering political factors."

The world's first permanent war crimes tribunal is based on a treaty adopted on July 17, 1998 and since ratified by 107 nations.