WASHINGTON, D.C.: While opinion polls on the U.S. military action against Iran show Americans clearly divided along party lines, most polls indicate opposition exceeds support.

Polls show that many Americans think the military action could make the United States less safe, even though they also see Iran as a threat to U.S. security.

There are also warning signs for Donald Trump as he faces the possibility of a long conflict that could cause serious economic problems.

On March 9, Trump gave mixed messages about how long the war might last. He suggested it could end soon, but also warned that the U.S. could use more force if Iran tried to disrupt the global oil supply.

Changing oil prices may already be worrying voters. Polls taken over the weekend found that most Americans are concerned the war could raise oil and gasoline prices. Many also believe the U.S. military action against Iran will last for several months or longer.

The polls show that most Republicans support the president. However, many are cautious about any response that might send U.S. troops into Iran.

Since Trump campaigned on putting "America first" and ending long overseas wars, the conflict with Iran could become a major political issue.

More Americans oppose the U.S. military action than support it. A new Quinnipiac University poll found that 53 percent of registered voters oppose the action, while about 40 percent support it and around 10 percent are unsure. A poll by Ipsos also found that more people disapprove of the strikes than approve of them.

Quick surveys by The Washington Post and CNN soon after the U.S. and Israel attacks also showed that more Americans opposed the military action than supported it.

However, a poll by Fox News found opinions were evenly split, with half of voters approving of the military action and half disapproving.

In the Quinnipiac poll, 55 percent of voters said they did not believe Iran posed an immediate military threat before the strikes. However, about six in ten voters in the Fox News poll said Iran is a real national security threat.

A poll by NORC at the University of Chicago and The Associated Press found that about half of U.S. adults were very concerned that Iran's nuclear program could directly threaten the United States.

Democrats and independent voters showed the highest level of concern, but about half of Republicans were also at least somewhat worried about the war pushing gas prices higher.

Fear of Gas Prices Worsening

An Ipsos poll conducted from March 6 to March 9 found that about two-thirds of Americans expect gas prices to worsen over the next year due to U.S. military action. Even among Republicans, more people believed prices would rise than fall. Democrats and independents strongly expect prices to increase.

On March 9, Trump said the United States would take further action against Iran if it tried to block the global oil supply.

Many Americans also doubt Trump's judgment about the war. In both the Quinnipiac and Fox News polls, about half of voters said the military action in Iran makes the U.S. less safe, while only about three in ten said it makes the country safer.

A CNN poll found that about half of Americans believe the strikes could make Iran more dangerous to the United States, while only about three in ten think they would reduce the threat.

According to the CNN poll, about six in ten Americans said they trust Trump "not much" or "not at all" to make the right decisions about using military force in Iran. Republicans generally trust him more than Democrats and independents.

A poll by The Associated Press and NORC taken before the strikes also found that 56 percent of Americans trusted Trump only a little or not at all to make the right decisions about using military force abroad.