The poll, conducted on Friday through Sunday, also showed the Republican president’s approval rating ticking higher to ‌37%, up three points from last month when his rating tied the lowest of his presidency.

Trump has offered shifting objectives for the conflict, such as aiding Iranians to topple their leaders, taking out Iran’s ballistic-missile capabilities and preventing it from obtaining a nuclear weapon.

The poll found that 69% of Americans — including four in 10 Republicans — think Trump has not “clearly explained the goals of US military involvement in Iran.”

White House spokeswoman Olivia Wales said Trump will not make decisions based on “fluid opinion ​polls” and reiterated the president’s resolve to prevent Iran from ever acquiring a nuclear weapon.

“What matters most to the American people is having a commander in chief who takes ​bold action to keep them safe,” Wales said.

Approval of the conflict has been below 40% since the US and Israel launched strikes ⁠on February 28 — a stark contrast to the opening months of other recent conflicts.

While each had different context, the Iraq War from 2003 to 2011 had the support of about 70% ​of Americans in its early months.

During the early days of the Afghanistan War, which lasted from 2001 to 2021, about 90% of the country backed the war, according to polling by Gallup.

‘No idea’ why US at war

Public disapproval of the war is weighing on Trump and his Republican Party ahead of the November midterm elections when the president’s allies will defend slim majorities in the US Congress.

“It’s not clear why we started a war with them. I have no idea,” said Alex Womack, a retired turbine repair specialist from Stockbridge, Georgia, who became a Republican in part because he liked how Republican President George H.W. Bush handled the Gulf War in ​1991.

Womack, who served in the US Marine Corps during that conflict, said his support for Trump has ebbed because of the war.

“I don’t think he’s doing very well, personally,” he said.

To ​date, 18 American soldiers have died in the conflict while thousands have died in Iran and in Lebanon, where fighters have battled Israeli forces.

The war has pushed gasoline prices sharply higher, a blow to the finances ‌of many Americans. ⁠

Gasoline prices are averaging just over $4 a gallon nationwide, up from about $3 a gallon just before the war started on February 28.

“This puts pressure on the party in a myriad of ways, all of them bad,” said Alex Conant, a Republican political strategist and a White House spokesman during the presidency of George W. Bush.

“The White House officials have been saying since January that they need to win economic arguments. It’s hard to win the economic arguments when you’re clearly focused on foreign policy.”

Independent registered voters in the latest Reuters/Ipsos poll said they were favouring the Democratic congressional candidate ​over the Republican by 36% to 20%.

Independent voters ​also favoured Democrats over Republicans on economic ⁠policy, the poll found.

Trump vowed to stay out of wars

In campaigning for the 2024 presidential election, Trump said he would keep the US out of enduring conflicts.

He initially estimated the Iran war would last four to five weeks.

He has bristled over comparisons to other wars, including the ​Vietnam War, which lasted two decades and claimed the lives of more than 58,000 US soldiers.

Rhyan Anderson, an independent from Fairburn, Georgia, ​who voted for Trump in ⁠2024, said he thinks Trump should focus on domestic problems rather than on helping Israel or other allies.

“My biggest thing is just focus on the people who are actually in the country,” said Anderson, who works two jobs in security and data collection and said he voted for Democrat Joe Biden in 2020.

“I know we have allies and things like that, but there’s a lot of people here ⁠that really ​need help.”

Since mid-March, the Reuters/Ipsos survey has asked respondents whether they support or oppose military strikes on Iran. ​At that time, 37% said they supported the war.

That compared to 27% approval on the day the war began, when the Reuters/Ipsos survey also gave respondents the option to choose unsure, which 29% did.

The latest Reuters/Ipsos survey, which was ​conducted online and nationwide, gathered responses from 1,246 US adults and had a margin of error of 3 percentage points in either direction.