WASHINGTON (AP) _ Air Force officials are calling for retirement of all 450 of the nation's Minuteman 2 intercontinental ballistic missiles in a move to save $400 million a year, according to a published report.

Defense Secretary Dick Cheney has received the green light to discuss the proposal with congressional leaders this week before any final decision, The Washington Post reported in Saturday's editions.

An Air Force spokesman, Col. Patrick Maloney, said Saturday when asked about the plan that the service does not discuss budget proposals until the budget becomes final.

The Post quoted officials as cautioning that President Bush might veto the idea before unveiling his fiscal 1991 budget to Congress on Jan. 29.

In another cost-cutting move, Cheney on Friday froze civilian hirings at the Defense Department, saying it was made possible by eased world tensions.

Department officials, however, said they did not know how much the work force will be reduced by the freeze.

The freeze lasts until Sept. 30 and applies to all Defense Department civilians worldwide, including part-time and temporary employees. The department currently employs 927,000 civilians full-time and another 123,000 on a temporary or part-time basis.

Up to 80,000 workers retire or otherwise leave that work force each year, the Pentagon said.

The Minuteman 2 carries a single warhead with an explosive force estimated at 1.2 megatons, or the equivalent of 1.2 million tons of TNT. The missiles are based at Malmstrom Air Force Base, Mont.; Ellsworth Air Force Base, S.D., and Whiteman Air Force Base, Mo.,

The Minuteman 2 is relatively inaccurate compared with later missiles. Published estimates say half the missiles launched would land within 1,200 feet to 2,000 feet of the point of aim.

Similar estimates for the 550 deployed Minuteman 3 missiles, which carry three smaller warheads, are from 600 feet to 700 feet.

Besides the Minuteman, the nation's land-based missiles include 50 MX Peacekeeper missiles with 10 warheads each. Counting other missiles and bombs, the Minuteman 2 force represents about 3.5 percent of the nation's strategic nuclear warheads.

The Bush administration has proposed building a new Midgetman single- warhead missile that could be moved about on giant trucks. Midgetman proponents say the mobile missiles would be much more difficult to hit than known, fixed positions such as current Minuteman silos.

Because they are old and inaccurate, the Minuteman 2 missiles have been candidates for retirement for some time. The administration told Congress last summer that a likely strategic nuclear arms treaty with the Soviet Union would mean significant reductions in missiles on both sides.