Ayotte did not accept LaHood's answer, saying "I can't go home and tell my constitutes with a straight face that this is paid for.
"We weren't planning on being in Iraq," she said. "The notion that we were going to be somehow having a full contingency in Iraq for the next 10 years, I don't think anyone who has looked at that war would come to that conclusion."
Democrats on the budget committee came to LaHood's defense.
"This body has a habit" of criticizing Congressional Budget Office reports lawmakers do not agree with, Sen. Mark BegichMark BegichThe future of the Arctic 2016’s battle for the Senate: A shifting map Trump campaign left out of Alaska voter guide MORE (D-Alaska) said.
"The pay-for is [Overseas Contingency Operations], which CBO has scored," Begich said. "I'm all for the pay-for. I have no interest in being in Afghanistan for 10 years with combat troops. I think that is a terrible policy."
LaHood told lawmakers on the budget committee Wednesday that Obama's transportation budget proposal would be "fully paid for."
"We will pay for the investments proposed under the surface transportation reauthorization proposal with the savings achieved from ramping down overseas military operations to do some nation-building right here at home," LaHood said in his opening remarks.