sentences:  Officials in the U.S. alliance believe Saudi Arabia and Pakistan have an understanding in which Islamabad would supply the kingdom with warheads if security in the Persian Gulf was threatened.A U.S. official told "The Times" that Riyadh could have the nuclear warheads in a matter of days of approaching Islamabad.Pakistan's ambassador to Saudi Arabia, Mohammed Naeem Khan, was quoted as saying that "Pakistan considers the security of Saudi Arabia not just as a diplomatic or an internal matter but as a personal matter."