On Israeli soil, U.S. presidential candidate Mitt Romney on Sunday declared Jerusalem to be the capital of the Jewish state and said the United States has "a solemn duty and a moral imperative" to block Iran from achieving nuclear weapons capability.

"Make no mistake, the ayatollahs in Iran are testing our moral defenses. They want to know who will object and who will look the other way," he said. "We will not look away nor will our country ever look away from our passion and commitment to Israel."

The presidential election hovered over the speech, with the Old City forming a made-for-television backdrop behind Romney, while some of his campaign donors listened in the audience.