Washington: US President Barack Obama is leading over his potential Republican challenger Mitt Romney by six points, a latest opinion poll has said.

The opinion poll results by The Washington Post and ABC news came a day after Obama said that he deserves to be re-elected for the second term given that his administration has successfully led the nation in revival of its economy.

Romney, who won his third primary state over the weekend, is the front runner among the four Republican presidential candidates. The poll was conducted last week.

Obama leads Romney 51 percent to 45 percent among registered voters.

Obama's overall approval rating stands at 50 percent, the highest in a Post-ABC News poll since a brief run above 50 percent immediately after Osama bin Laden was killed in May last year, it said.

But at the same time, 46 percent continue to disapprove.

"Among registered voters, 49 percent say Obama's performance warrants a second term; exactly as many say it doesn’t," the Washington Post said.

"Obama remains a polarizing figure, with Americans closely divided on whether he deserves reelection as well as on many aspects of his performance in office. Although better than they were a few months ago, his ratings on handling the economy and job creation remain negative, with intensity continuing to run against him," the daily said.