Updated

President Obama will keep his promise to reach a solution on federal funding of abortions but that is not the centerpiece of his health care overhaul, White House Press Secretary Robert Gibbs said Tuesday.

The spokesman offered his assessment after a key anti-abortion Democrat in the House said he is now confident a deal will be struck that resolves a critical dispute on federal funding of abortion procedures.

"This president is willing to keep the promise that we've made throughout this," Gibbs said in an interview Tuesday on ABC's "Good Morning America."

But, Gibbs added, "This is not a bill about abortion. This is about health care reform."

Gibbs told reporters later Tuesday that he believes the House will vote on health care by March 18.

Rep. Bart Stupak, of Michigan, has threatened to bring down any bill that allows federal funding of abortion. He has emerged as a spokesman for about a dozen House Democrats who supported health legislation approved by the House in November but contend a $1 trillion version that passed the Senate the next month would authorize federal abortion subsidies.  They insist on restoring stiffer restrictions Stupak added to the House measure.

Stupak had said last week that nothing had changed and he didn't think the House leaders had the votes to pass the bill.

But on Monday he said he will resume talks with House leaders this week in a quest for wording that would impose no new limits on abortion rights but also would not allow use of federal money for abortions.

"I'm more optimistic than I was a week ago," Stupak told The Associated Press.

"The president says he doesn't want to expand or restrict current law (on abortion). Neither do I," Stupak said. "That's never been our position. So is there some language that we can agree on that hits both points -- we don't restrict, we don't expand abortion rights? I think we can get there."

Michelle Begnoche, a spokeswoman for Stupak, clarified Tuesday that Stupak had not reached a deal yet.

Last Thursday, Stupak "had meaningful discussions" with Rep. Henry Waxman, D-Calif., and Majority Leader Steny Hoyer, D-Md., Beghnoche said. "Congressman Stupak expects further meetings this week and remains optimistic that language can be worked out."

Stupak's hard-line stand has made him a lightning rod for abortion-rights supporters. Some accuse the 18-year lawmaker, a Roman Catholic, of allowing religious beliefs and personal opposition to abortion to jeopardize health reform. He denies it, saying the pro-choice side raised the issue by making the health bill a vehicle to expand abortion rights.

Anti-abortion lawmakers last summer urged House leaders to keep abortion out of the health debate "because it's too divisive," Stupak said. "So what did they do? They injected it into the debate. Everyone thinks I did; I did not."

"Current law is, we do not use federal funds for abortion, period," Stupak said in a Feb. 25 interview on Fox News. "In any program, whether its children's health initiative, whether its Medicaid, whether its Medicare, whether its Department of Defense, we do not use public funds, taxpayer funds for abortion."

Stupak is among a handful of pro-life Democrats opposed to the current abortion language in the health bill.  The Susan B. Anthony List, a non-partisan pro-life women's group, announced Tuesday that it is kicking off a $500,000 pro-life media campaign in eight pro-life Democrats' districts, including Reps. Jason Altmire, D-Pa., and Rep. Brad Ellsworth, D-Indiana.

"Our polling last week showed overwhelming majorities of voters in these districts oppose abortion funding in healthcare reform legislation," the group's president, Marjorie Dannenfelser, said in a statement Tuesday. "Yet despite this overwhelming support for pro-life protections, there are signs that some members who originally voted for the Stupak Amendment are wavering."

Stupak's stand has generated mixed feelings among his constituents in Michigan's Upper Peninsula, which tends to be socially conservative but leans Democratic because of organized labor's strong influence.

The lawmaker, who first won his seat in 1992, held an evening town hall of about 125 people who came to the high school library in the Lake Huron town of Tawas City.

He defended his position on the abortion issue while insisting health care reform is necessary, and described the House version as "a right-to-life bill," saying some 45,000 Americans die annually for lack of good health care.

Donna Reminder, 77, said she didn't like abortion but didn't want Stupak to let the issue keep him from supporting a health bill.

"I'd say go for it anyway. We need it," Reminder said during lunch at a senior center. "Not having good health care is killing a lot of people."

Ellen Smith, administrator of a company that operates 10 medical clinics across the region, said Stupak should hold his ground.

"I don't believe abortion should be paid for with tax money," Smith said in an interview.

Jim McKimmy, the Democratic chairman in a neighboring county, urged Stupak to accept a compromise on abortion if necessary to save the bill.

"Please don't let it go down to defeat over a single issue," he said.

But Gaylord resident Don Koeppen said backing down on abortion could cost Stupak re-election.

"To me it's a matter of sticking to his guns," said Koeppen, who said he leans Republican but has voted for Stupak in recent elections. "Many people would be extremely disappointed if he changed his position."

The Associated Press contributed to this report.