Respondents, by 38 percent to 26 percent, said they think Obama can handle the situation in the two countries better than his Republican rival, UPI-CVOTER results released Monday indicated.
Fourteen percent of those asked said say neither candidate can make a success of the situations and 12 percent said both Obama and Romney were equally competent.
The United States withdrew from Iraq military last year and is scheduled to pull out fully from Afghanistan by 2014.
Although Romney has indicated the United States should be tougher on Iran, voters said they trust Obama over Romney by 10 percentage points -- 36 percent to 26 percent -- to better handle the situation with Iran. Fourteen percent said they neither candidate could handle a conflict with Iran and 10 percent said they had equal confidence in both.
Thirty-three percent of respondents said Obama would do more to maintain America's stature on a global stage than Romney, favored by 29 percent.
Obama leads Romney 32 percent to 30 percent on "moral values," results indicated.
Voters were split at 30 percent apiece on which candidate could streamline big government and bureaucratic spending, results showed.
Romney led Obama on one question, the poll found. By 32 percent to 29 percent, voters said they think Romney would do a better job on illegal immigration.
Results are based on nationwide interviews with 3,000 registered voters conducted Sept. 8-14. The margin of error is 3 percentage points.