Election Day is less than a week away and polls released on Thursday indicated that President Barack Obama is leading Republican candidate Mitt Romney in Iowa, New Hampshire and Wisconsin.

According to CNN, these are the three states that are being fiercely contested in these final days of the campaign.

In Iowa, the president is leading Romney 50-44 percent, according to a NBC News, Wall Street Journal and Marist poll. This result is a bit higher than it was earlier in October.

CNN reported that a poll released Wednesday showed a much tighter race in the Hawkeye State. A University of Iowa survey put Obama at 42.7 percent and Romney at 41 percent.

Dr. Lee M. Miringoff, director of the Marist College Institute for Public Opinion, said the president's lead in Iowa is due to those who have voted early or plan to do so, also including many independents.

"Obama has a 21 point lead among independent voters who plan to cast an early ballot while Romney is up 9 points among independents who plan to vote on Election Day," he said. 

The president's lead in Iowa was boosted by the high support he got early in the race.

Forty-five percent of the sample had already cast their ballots or said they were planning to vote before Election Day. Obama led Romney 62-35 percent among those people and Romney led Obama by 55-35 percent among those who said they'd vote on Election Day.

Although these numbers are quiet distant, the race is much closer in New Hampshire. President Obama holds a 49 percent lead and Romney ranked in with 47 percent.

"The battle for New Hampshire's four electoral votes has gotten very close," Miringoff said. "The president is not getting anywhere near what he got four years ago when he carried the state by nine points."

CNN confirmed that the New Hampshire survey released on Thursday is the first non-partisan poll of the state, conducted after the last presidential debate in October.

Polls taken before the final debate showed Romney with a two point lead over Obama: 49 to 47 percent. However, the polls taken recently show that Obama leads Romney 49-41 percent, which is a deep 8 percent lead for the president.

Also, recent polls in Wisconsin released on Wednesday indicate that 51 percent of likely voters in that state prefer Obama while 43 percent support Romney.

"President Obama is advantaged by voters who plan to vote early," Miringoff added. "But Romney benefits from greater enthusiasm among his supporters."