The White House on Thursday threatened to veto the 2013 defense budget bill now on the Senate floor if Congress does not make a number of changes to the legislation, ranging from limits on the transfer of detainees from Guantanamo Bay to cuts in the size of the Pentagon’s civilian and contractor workforce.

“If the bill is presented to the President for approval in its current form, the President’s senior advisers would recommend that the President veto the bill,” noted the statement issued Thursday by the White House’s Office of Management and Budget.

The administration objected to language in the National Defense Authorization Act that would reduce funding for the civilian and contractor workforce by a rate at least equal to the percentage of funding saved from planned reductions in military personnel.

“The Administration believes the size of the civilian workforce should be determined based on workload and funding, not on arbitrary comparisons to the military,” the statement said.

On Wednesday, Sen. Benjamin L. Cardin (D-Md.) introduced an amendment co-sponsored by seven other Democrats to change the provision, which he said would lead to “draconian” cuts costing 36,000 civilian jobs and tens of thousands of Defense contractor jobs between 2013 and 2017.

The White House also urged approval of proposed changes to the Tricare military health system, including increased fees that the OMB said are needed to “control the spiraling DOD health-care costs.”

The proposed restrictions on the use of funds to transfer prisoners from the military prison at Guantanamo Bay are similar to those in past versions of the legislation.

“Since these restrictions have been on the books, they have limited the Executive’s ability to manage military operations in an ongoing armed conflict, harmed the country’s diplomatic relations with allies and counterterrorism partners, and provided no benefit whatsoever to our national security,” the OMB statement said.

Sen. Carl Levin (D-Mich.), chairman of the chamber’s Armed Services Committee and the chief sponsor of the bill, had no immediate comment on the White House statement, a spokeswoman said. Levin is pushing the Senate to take action this week on the annual bill, which authorizes defense activities for the fiscal year that began in October.

Before being sent to President Obama, the Senate version will have to be reconciled with the bill already passed by the House.

The administration also “strongly” objected to language that is said would limit the Defense Department’s ability to procure alternative sources of energy for the military, including bio­fuels. The language was stripped from the bill by the Senate by a 62 to 37 vote Wednesday, but it remains in the House version.

The Senate on Wednesday also approved an amendment to the defense bill to require the Pentagon to create a comprehensive and standardized suicide prevention program.

The military has been plagued by increases in the number of suicides. As of the end of October, the number of suspected suicides by active-duty soldiers had reached 166, one more than the total for 2011.

“I think everyone in this body knows about, and is distressed by, the alarming rate of suicide and the mental health problems in our military and veterans populations,” Senate Veterans Affairs Committee Chairman Patty Murray (D-Wash.) said on the floor.

The legislation would also expand eligibility for some Department of Veterans Affairs mental health services to family members and strengthen oversight of the Pentagon’s mental health programs and the Integrated Disability Evaluation System established by VA and the Defense Department.

It would also promote the use of Iraq and Afghanistan veterans to provide peer counseling for fellow veterans, and require VA to establish accurate and reliable measures for mental health services.

Implementing the amendment would cost about $25 million over five years, according to an estimate from the Congressional Budget Office.