Skeptical U.S. lawmakers told Pentagon leaders Wednesday they did not like the department's proposed 2015 defense budget, but acknowledged painful cuts to military personnel and popular weapons systems were due to spending caps approved by Congress.

Reacting to the new Pentagon budget unveiled this week, members of the Senate Armed Services Committee expressed concern about plans to slash the size of the Army, curb the growth of military compensation, and retire popular weapons systems such as the entire fleet of A-10 "Warthog" tank-killer aircraft. "This administration's misguided budget priorities are robbing our military men and women of the tools they need to defend the nation against growing threats," said Senator Jim Inhofe of Oklahoma, the top Republican on the committee. Even the panel's Democratic chairman, Senator Carl Levin of Michigan, questioned whether the resources provided to the Defense Department were "adequate to enable our military to meet its national security missions."

The Pentagon's 2015 spending plan unveiled on Tuesday begins to look beyond the wars of the past 13 years, calling for a smaller overall military to generate savings that can be used to ensure training and modernization at a time of reduced budgets. The plan requires a Pentagon base budget of $496 billion, remaining virtually flat for a third consecutive year. It seeks an additional $79.4 billion in war funding, but officials said it was a place-holder value that would be replaced once the size of the post-2014 U.S. force in Afghanistan is decided.

The new budget comes as the Pentagon tries to slash nearly $1 trillion in projected defense spending over a decade as required under the Budget Control Act of 2011, which set caps on outlays for national security. The Pentagon is currently operating under a two-year deal approved by Congress which provided some relief from the budget cuts. But the larger cuts will return in the 2016-2019 fiscal years under the law as it stands, a move Pentagon officials say would be harmful to national security.

The Pentagon's proposed 2015 budget urges Congress to give the military an additional $26 billion above the spending lid for the year to be used largely for training and modernization. It also ignores the budget caps for the 2016-2019 fiscal years, asking for $115 billion more than the law allows during that time frame. Pentagon documents said returning to higher-level cuts would increase security risks and lead to a military too small to meet the needs of U.S. strategy. "The risks will grow and the options that we can provide the nation will dramatically shrink," Army General Martin Dempsey, the military's top uniformed officer, told the committee.

Lawmakers expressed skepticism about the budget's proposals for military compensation reform, such as lower pay increases, a reduction in the housing allowance, and a cut in subsidies for commissaries where many troops shop for food and clothes. The request was unpopular among lawmakers, some of whom face election this year and hoped to delay a decision until after compensation reform panel reports to the Pentagon next year. "Doesn't it make more sense to see what the study says before we go about reducing the (commissary) subsidy in a significant way?" asked Republican Senator Saxby Chambliss of Georgia.

Senator Kelly Ayotte, a New Hampshire Republican, fenced with Dempsey and Defense Secretary Chuck Hagel over the plan to retire the Air Force's fleet of A-10 close air support aircraft. "Some of the biggest advocates for the platform have been your fellow soldiers," said Ayotte, whose husband was an A-10 pilot. Dempsey agreed, noting he was probably the only one in the room who had been rescued by one.

"The A-10 is the ugliest, most beautiful aircraft on the planet," Dempsey said. But he added other planes could provide close air support for the Army, as Air Force chief General Mark Welsh -- himself an A-10 pilot -- would testify.