Visiting U.S. President George W. Bush on Thursday reiterated an "unbreakable" relationship with Israel, vowing to stand by the Jewish state's side against its enemies.

U.S. President George W. Bush pauses during applause in his speech to the Knesset in Jerusalem May 15, 2008.

"Some people suggest that if the United States would just break ties with Israel, all our problems in the Middle East would go away. This is a tired argument that buys into the propaganda of the enemies of peace, and America utterly rejects it," Bush told a special session of the Knesset, the Israeli parliament, in Jerusalem.

"Israel's population may be just over 7 million. But when you confront terror and evil, you are 307 million strong, because the United States of America stands with you," Bush added.

Pinpointing Iran, whose senior leaders have repeatedly made threatening remarks against Israel, Bush said the United States and Israel have a concerted goal of opposing Tehran's efforts to obtain nuclear weapons.

"Permitting the world's leading sponsor of terror to possess the world's deadliest weapon would be an unforgivable betrayal of future generations," he said. "For the sake of peace, the world must not allow Iran to have a nuclear weapon."

U.S. President George W. Bush (L) hugs Israeli President Shimon Peres (R) following a speech to the Knesset in Jerusalem May 15, 2008. Speaker of the Knesset Dalia Itzik is in the foreground.