Vice President Joe Biden and President Barack Obama at the Democratic National Convention on Sept. 6, 2012. (AP Photo/J. Scott Applewhite)

(CNSNews.com) - President Barack Obama's job approval climbed to 52 percent in the Gallup poll for the three-day period of Sept. 4 through Sept. 6, which is the highest Obama's approval has been since the three-day period ending June 1, 2011, when it hit 53 percent.

On Sept. 3, the day before the Democratic National Convention started, Obama's approval had been just 45%.

At the same time, Obama picked up ground over Republican presidential candidate Mitt Romney. Last week, according to the Gallup tracking poll of the presidential race, Romney actually lost a point over the course of the Republican National Convention. Romney went from leading Obama 47 percent to 46 percent for the seven-day period that ended on on Aug. 27 to trailing Obama 46 percent to 47 percent for the seven-day period that ended on Sept. 3.

Since Sept. 3, Obama has picked up another point in the Gallup poll while Romney has lost one. Thus, for the seven-day period ending on Sept. 6, Obama led Romney 48 percent to 45 percent.

Gallup says its seven-day presidential tracking poll is based on interviews with about 3,050 registered voters and has a margin of error of +/- 2 percentage points.