Also on Monday, a Washington Post survey found 46 percent approved of Obama’s job performance, with 50 percent disapproving.
The dip in Obama's approval was attributed to rising national concern over higher gas prices.
The Post survey showed nearly two-thirds of voters disapprove of how Obama is handling gas prices. Sixty-five percent disapproved of his performance on the issue, while 26 percent approved.
The concern over gas prices was overshadowing other reports suggesting the economy was gradually improving, the poll also found. Fifty-nine percent in that poll said they disapproved of how Obama had handled the economy, and 50 percent "strongly" disapproved of his performance.
A Gallup poll also released on Monday showed Obama with a 49 percent approval rating, and a Bloomberg National Poll released Wednesday found that 48 percent of those surveyed approve of the job the president is doing.
Wednesday's Reuters poll, however, provides more positive signs for the Obama campaign, finding that Americans' confidence in the improvement of the economy is rising, up to 37 percent from 32 percent last month.
Reuters also shows Obama besting his likely GOP rivals. Obama tops Mitt Romney 52 percent to 41 in a head-to-head match-up, and former Pennsylvania Sen. Rick Santorum 52 percent to 42.
Obama campaign officials are confident in the president's reelection chances, but concerns about rising gas prices and growing tensions in Afghanistan have provided the team with its first test.
White House officials have sought to address both issues by putting Obama in front of the public.
The president has delivered speeches touting his energy policy and yesterday offered remarks supporting the U.S. mission in Afghanistan, days after a rogue American soldier was suspected of killing 16 civilians.
The Reuters poll was conducted via telephone last week and has a margin of error of 3 to 4 percentage points.