ISLAMABAD: The US ambassador to Pakistan pressed the country's president Monday to release an American official who Washington says was illegally detained after he shot and killed two men in Lahore.

Ambassador Cameron Munter's meeting with President Asif Ali Zardari in Islamabad followed repeated public demands for the American's freedom.

The US has said the American, who has been identified by Pakistanis as Raymond Allen Davis, acted in self-defense when he shot the two men on Jan 27 and must be released because he has diplomatic immunity.

Munter told Zardari that ''Pakistan must comply with its obligations under international law and immediately release the American diplomat illegally detained in Lahore,'' according to US Embassy spokeswoman Courtney Beale.

Presidential spokesman Farhatullah Babar confirmed the meeting took place but refused to comment on details of the discussion.