NORFOLK, Virginia (AP) - The Air Force is grounding about a third of its active-duty combat aircraft because of automatic, across-the-board spending cuts imposed by the US government.

The stand-down will affect units stationed in the US, Europe and the Pacific. Those units include fighter, bomber, aggressor and airborne warning and control squadrons.

Air Combat Command at Joint Base Langley-Eustis in Hampton, Virginia, made the announcement on Tuesday.

Some units deployed that include F-16s, F-22s, A-10s and B-1s will stand down after they return home from their deployments. Other units began on Tuesday.

The Air Force says the stand-down is the result of cuts to the command's operations and maintenance account. The Air Force says it must reduce its flying by about 45,000 fewer training hours before Oct 1 than it previously planned.