Proposed cuts in Department of Veterans Affairs spending on major construction and non-recurring maintenance threaten to derail efforts to update the department’s aging infrastructure, the chairman of the Senate Veterans Affairs Committee said Wednesday.

Sen. Patty Murray (D-Wash.), who said that funding levels are “deeply troubling,” raised the concerns at the committee’s hearing on the proposed fiscal year 2013 budget.

At the current level of funding, it would take the VA more than 25 years to complete its 10-year plan, said Raymond Kelley, legislative director for the Veterans of Foreign Wars.

Despite a 2013 budget that includes a 4.5 percent increase in discretionary spending for the VA, the request for major construction is $532 million, down from $1.074 billion in 2011 and $590 million in 2012. The VA’s 10-year construction plan could cost as much as $65 billion, Murray said.

“Despite this plan, for the past two years VA has requested only a fraction of the amount it needs,” Murray said. “I am disappointed at the size of the gap between the funding we need to bring facilities up to date and the funding requested from the Congress.”

With 5,300 buildings, some of them more than 60 years old, the VA faces a “monumental task” in improving facilities, which ­increasingly are being more heavily used, Kelley said.

The concerns were echoed by representatives of other veterans service organizations testifying at the hearing.

“Clearly, if this underfunding continues, VA will never fix its identified deficiencies within its 10-year plan,” said William Schrier, representing the American Legion.

The $532 million in new budget authority for major construction includes funding for medical facilities in Dallas, Seattle, St. Louis and Palo Alto, Calif., ­according to the VA.

The money will also be used to remove asbestos and other hazardous waste from VA buildings and to improve facility security.

The VA has a separate request of $608 million for projects to improve and alter a variety of VA facilities around the country. The figure represents an increase from $467 million last year and $482 million this fiscal year.

The concerns come against a backdrop of increased demand for VA services from veterans ­returning from Iraq and Afghanistan.

“The big elephant in the room is the 1 million returning veterans,” said Sen. Scott Brown (R-Mass.).

“History suggests that VA’s requirements from these two operations will continue to grow long after the last combatant leaves Afghanistan — maybe as much as a decade, maybe even more,” VA Secretary Eric K. Shinseki told the committee.

Shinseki noted that Iraq and Afghanistan veterans are using VA services “at unprecedented levels.” Out of 1.4 million who have returned from service in those wars, 67 percent have used some VA benefit or service — “a far higher percentage than those from previous wars,” Shinseki said.