JERUSALEM: U.S. Republican candidate Mitt Romney, presenting himself as Israel's best friend in the Nov. 6 presidential election, said on Sunday that "any and all measures" must be used to keep Iran from developing a nuclear weapon.

A top aide said Romney would support an Israeli military strike if all options had been exhausted, but the candidate himself balked at repeating that position.

In a foreign policy speech in Jerusalem, Romney voiced strong support for the alliance between the United States and Israel and seemed to suggest that President Barack Obama had let
the relationship flounder.

 "We cannot stand silent as those who seek to undermine Israel voice their criticisms. And we certainly should not join in that criticism. Diplomatic distance in public between our nations emboldens Israel's adversaries," said Romney, the walls of the Old City lining the hilltop behind him.

The former Massachusetts governor was in Jerusalem on the second leg of a trip to strengthen his foreign policy credentials in his race to unseat Obama.

 "We should employ any and all measures to dissuade the Iranian regime from its nuclear course, and it is our fervent hope that diplomatic and economic measures will do so. In the final analysis, of course, no option should be excluded. We recognize Israel's right to defend itself, and that it is right for America to stand with you," he said.

Though he adopted an aggressive tone, Romney did not go as far as his senior foreign policy advisor, Dan Senor, who said earlier: "If Israel has to take action on its own, in order to stop Iran from developing that capability, the governor would respect that decision."

The aide's comments put Romney at odds with Obama's efforts to press Israel to avoid any preemptive strike before tough Western economic sanctions against Iran run their course.

Romney, however, refused to repeat them when asked by CBS' "Face the Nation".

"Well I think because I'm on foreign soil I don't want to be creating new foreign policy for my country or in any way to distance myself in the foreign policy of our nation. But we respect the right of a nation to defend itself," Romney said.

The failure of talks between Iran and six world powers to secure a breakthrough in curbing what the West fears is a drive to develop nuclear weapons has raised international concern that Israel may opt for a military strike. AGENCIES