President Barack Obama at the Pentagon
President Barack Obama at the PentagonReuters

Only one in three Americans approve of President Barack Obama's handling of the situation in Iran, according to a new Gallup poll. This is his lowest rating among eight issues measured in the survey.

These data are from an Aug. 5-9 Gallup poll, conducted as Congress debates the Iran nuclear deal. In February, noted Gallup, Americans gave Iran the lowest favorable rating of 22 countries, and a strong majority felt its development of nuclear weapons posed a "critical" threat to the US.

While 56% of Democrats approve of Obama's handling of the situation in Iran, only a small minority of Republicans – 10% – do so.

“If Congress signs off on the nuclear deal with Iran, it is possible that Obama's approval rating on that front could improve,” estimated Gallup. “But if Congress votes the deal down, Obama's leadership will have suffered a major blow that could further diminish his rating on Iran, and perhaps his overall job performance rating.”

Race relations remains the issue Obama receives the greatest approval on, at 46%. However, this is down five percentage points from when Gallup last measured it in 2013.

Aside from Obama's handling of Iran, his approval is low on immigration, at 36%. However, this score is up four points from the last reading in August 2014.

About four in 10 Americans approve of the president's performance on the economy and foreign affairs – similar to the approval he received on these issues in February. His economic approval rating is “essentially the same as the average throughout his presidency.”

At 39%, his foreign affairs approval rating is among the lowest of his administration, though it is improved from last fall, when it was 31%.