The United States has given Pakistan a deadline till July to launch a military offensive in the restive North Waziristan tribal region for capturing five most wanted al-Qaeda and Taliban terrorists, including Ayman al-Zawahiri, Mullah Omar and Ilyas Kashmiri.

The Pakistani security forces have been asked to capture al-Zawahiri, Omar, Kashmiri, Sirajuddin Haqqani and Atia Abdur Rehman, either in a unilateral or joint military action before July — the month when NATO and allied forces will begin withdrawing from Afghanistan.

The U.S. demand has set alarm bells ringing in Pakistani civil and military circles, The News daily reported on Wednesday, quoting unnamed sources.

Pakistan's security forces have been reluctant to launch an offensive in North Waziristan, despite sustained pressure from the U.S.