WASHINGTON (Reuters) - The White House proposed on Monday to spend $671 billion on the military next year, handing the Pentagon a short-term boost even as it prepares for tighter budgets in coming years.

The Obama administration budget proposal for fiscal 2012 includes $118 billion for the wars in Afghanistan, Iraq and Pakistan, on top of the base budget of $553 billion.

That base budget figure is $22 billion above the level enacted for 2010, setting a new record even as the rest of the government faces a freeze in federal spending.

The budget would include $113 billion for procurement of weapons and services, down from about $120 billion projected a year ago, plus nearly $77 billion for research and development, roughly on par with the previous plan.

U.S. defense contractors including Lockheed Martin Corp, Boeing Co, Northrop Grumman Corp have been bracing for slower growth in defense spending after a decade of double-digit increases that have nearly doubled the Pentagon's core budget since September 11, 2001.

The proposed defense budget unveiled on Monday is largely in line with plans announced last month by Defense Secretary Robert Gates to cut $78 billion from the Pentagon's core spending over the next five years.

Total spending on national defense in the proposed budget would be $728.4 billion, a figure that includes spending on nuclear weapons and health care and retirement, up from $721.3 billion in fiscal 2010.

Big priorities would be cybersecurity, to be funded with $2.3 billion, satellites and nuclear security, according to a budget document submitted to Congress on Monday.

At the same time, the Pentagon proposed to cut $13 billion from what it deemed unneeded "niche" weapons, including a $14-billion landing craft being designed by General Dynamics Corp, a surface-launched, medium-range missile being developed by Raytheon Co for the Army, as well as the SM-2 surface-to-air missile that Raytheon builds for the Navy.

(Reporting by Andrea Shalal-Esa; Editing by Tim Dobbyn)