Most Americans would back U.S. strike over Iran nuclear weapon: poll

WASHINGTON (Reuters) - A majority of Americans would support military action against Iran if there were evidence that Tehran is building nuclear weapons, even if such action led to higher gasoline prices, a Reuters/Ipsos poll showed on Tuesday.

The poll showed 56 percent of Americans would support U.S. military action against Iran if there were evidence of a nuclear weapon program. Thirty-nine percent of Americans opposed military strikes.

Asked whether they would back U.S. military action if it led to higher gasoline prices, 53 percent of Americans said they would, while 42 percent said they would not.

The Reuters/Ipsos poll also found that 62 percent of Americans would back Israel taking military action against Iran for the same reasons.

U.S. President Barack Obama has said all options are on the table in dealing with Iran's nuclear program, but he has encouraged Israel to give sanctions against Iran more time to have an effect.

Iran says its nuclear program is peaceful.

Higher gasoline prices, which have risen in part due to tension in the Middle East, have put political pressure on Obama as he fights for re-election later this year.

The president, a Democrat, has also faced criticism from his potential Republican rivals for being too soft on Iran and not supportive enough of Israel.

The poll showed Republicans were more willing to support military action by the United States or Israel than Democrats. Seventy percent of Republicans would back U.S. action, while 46 percent of Democrats and 51 percent of independents said the same.

The breakdown was similar when respondents were asked to factor in gasoline prices or their support of an Israeli military move.

"What we're seeing is kind of a general trend that we always see, that Republicans tend to be more hawkish than Democrats or independents," said Ipsos pollster Cliff Young. "Historically Republicans have been much more security-centric."

A potential conflict with Iran has cast a foreign policy shadow over the U.S. election, which is expected to be dominated by voter concerns over the domestic economy.

Obama accused Republican presidential candidates earlier this month of "beating the drums of war" while failing to consider the consequences.

Former Pennsylvania Senator Rick Santorum, one of the top Republican presidential contenders, told the powerful pro-Israel lobby group AIPAC: "If Iran doesn't get rid of nuclear facilities, we will tear them down ourselves."

Despite Americans' signs of tolerance of higher gasoline prices in the poll, Obama's chances of getting re-elected are threatened by rising prices at the pump.

The poll was conducted from March 8-11 among 1,084 adults across the United States. It has a margin of error of 3.1 percentage points.

(Editing by Cynthia Osterman)