If there were still any doubts about the extent to which Mitt Romney is competing to win the Iowa caucuses, they can now be erased.

 Romney’s campaign is airing its first television ad in Iowa this week. He has committed to participating in two upcoming Iowa debates. And one of his top surrogates, New Jersey Gov. Chris Christie, will campaign on Romney’s behalf in populous Polk County next week. 

Romney dispatched one of his sons, Josh, to the campaign’s new Des Moines on Wednesday to hold a meeting with campaign volunteers. In addition, longtime supporter Mike Leavitt, a former Utah governor and health and human services secretary under President George W. Bush, will soon campaign in Iowa on Romney’s behalf, according to Iowa Gov. Terry Branstad (R), who has not endorsed in the race.

“In the closing weeks before the caucuses, we will continue to make the case that Mitt Romney is the best candidate to beat Barack Obama,” Romney spokeswoman Andrea Saul said in a statement Thursday. “Mitt Romney has always said that he would campaign and compete in Iowa.”

After spending $10 million in the state in 2008, only to lose the crucial Iowa caucus to former Arkansas governor Mike Huckabee, Romney’s campaign has carefully engineered expectations for the 2012 caucuses, which take place Jan. 3, just five weeks from now.

His visits to the state had been sporadic, and he maintained only a skeletal staff, investing more heavily and openly in other early states, chief among them New Hampshire.

But sensing an opening, as the conservative Iowans who were unlikely to support Romney split among several rival campaigns, the former Massachusetss governor is intensifying his Iowa efforts. He has made several trips there this fall, most recently to a Des Moines insurance company the day before Thanksgiving.

Saul said Romney “looks forward to participating in the two upcoming Iowa debates” – the Dec. 10 debate in Des Moines sponsored by ABC News and the Des Moines Register, and the Dec. 15 debate in Sioux City sponsored by Fox News and the Iowa Republican Party.

 Romney’s Iowa ad is a positive, 30-second spot that presents Romney as “a conservative businessman.” It is almost identical to the one his campaign released on Wednesday and is airing in New Hampshire. Details of the buy were not immediately available.

The ad, titled “The Right Answer,” shows an assortment of black-and-white photographs of Romney on the campaign trail and color footage of him at the Sept. 12 CNN debate in Florida. There are shots of Romney at the Iowa State Fair, meeting with workers at a metal shop in Dubuque and receiving the endorsement of Sen. John Thune (R-S.D.) at an event in Des Moines.

 “Going on television is just another tool in getting Mitt Romney’s message out that Barack Obama has failed as a president, and that [Romney] is the best choice to grow the economy, cut spending and create jobs,” Saul said. 

The ad is narrated by one of Romney’s debate answers, where he talks about spending his life in the private sector and leaning how economies grow. He says the country needs to balance the federal budget by cutting spending.

“The right answer for America is to stop the growth of the federal government and to start the growth of the private sector,” Romney says.

 Christie is set to campaign in Iowa on Dec. 7 in Polk County, which includes the state capital of Des Moines, and Romney is due to return to the state next week. News of Christie’s visit was first reported overnight by The Des Moines Register and confirmed by Romney campaign officials.

Staff writer Dan Balz contributed to this report from Orlando, Fla.