Hagel said that Washington remains in lockstep with Israel in that country's efforts to thwart Iran from developing a nuclear weapon.
"It's really a threat to the peace in the world, for no reason whatsoever," he said of Tehran's nuclear ambitions.
Hagel also tried to tamp down some of the aggressive rhetoric coming out of Jerusalem, pushing for unilateral action against Iran's enrichment program.
"You have a choice," Hagel said. "You don't show animosity to Iran. You simply tell them not to make the Middle East a terrible place of threats and the mass destruction weapons."
President Obama and Israeli Prime Minister Benjamin Netanyahu have clashed over how much time is left to prevent a nuclear- armed Iran, with the Israelis believing that the program is much closer to weapons capability.
Director of National Intelligence James Clapper told Congress last week that U.S. assessments of Tehran's program fall in line with the White House's claim that Iran remains years away from developing a ballistic weapon.
That said, Hagel told reporters earlier on Monday that there was “no daylight at all” on the need to prevent Iran from becoming a nuclear power.
His visit to Israel was part of a week-long goodwill trip to various U.S. allies in the Mideast, with scheduled stops in Jordan, Israel, Saudi Arabia, Egypt and the United Arab Emirates.
Hagel's comments come months after congressional Republicans bashed the DOD chief for his positions on Israel and Iran during February's Senate confirmation hearings.
Since then, Hagel “has made a concerted effort to [build] … good relationships with Congress,” a senior defense official told The Hill earlier this month.
That charm offensive by DOD to Congress, which continued in Israel with the Pentagon chief's comments on Iran, has already seemed to pay dividends.
“I feel very good about him at this point … I like his demeanor, I like what he says, and I like the way he he’s acting” as defense secretary, House Armed Services Committee chair Rep. Buck McKeon said last week.
Signs that Hagel’s efforts are working go beyond McKeon.
“So far, so good,” Sen. Lindsey Graham (R-S.C.) said of Hagel’s tenure.
Graham added that he supported the way Hagel was handing the growing crisis in North Korea and the U.S. drawdown in Afghanistan.
Sen. Saxby Chambliss (R-Ga.) said it was “still too early to tell” if Hagel has done enough to bring Senate Republicans around to his side.
“I [still] do not think he handled his confirmation … that well, but [Hagel] is a good guy and his heart is in the right place,” Chambliss said.