The survey found that 32% of registered voters approve of Trump’s job performance, while 58% disapprove, Anadolu Agency reported.
A majority of voters, 60%, said they oppose the US military action against Iran, while 34% support it.
Opposition was highest among Democrats at 89% and independents at 69%, while 74% of Republicans backed the military action against Iran.
The survey showed 74% of voters oppose sending US ground troops into Iran, compared with 19% who support such a move.
More than half of voters, 55%, said they believe the military action will last about a year or longer, while 35% expect it to continue beyond a year.
The poll also found 54% of voters believe the US is not winning the war with Iran, while 36% said it is winning.
Trump's ratings were also negative on the economy, foreign policy, trade and immigration.
Only 34% approved of his handling of the economy, while 62% disapproved.
While 59% of voters said the economy is getting worse, 49% said they are financially worse off than they were a year ago.
On immigration, 40% approved of Trump’s handling of the issue, while 57% disapproved.
The poll surveyed 963 registered voters nationwide from July 23 to 27.