The US Air Force has begun grounding about a third of its combat aircraft in response to deep budget cuts that began to take effect in March.

The move will affect units in the US, Europe and the Pacific.

Air Force Gen Mike Hostage said aircraft would be grounded on a "rotating basis" to focus on "fulfilling critical missions".

Separately, the US Navy said the cuts will force it to ground its Blue Angels air show team for the rest of the year.

The Air Force's budget for the fiscal year ending in October is being reduced by $591m (£386m).

'Risk' to airpower

The cuts are part of the series of deficit reduction measures that began to take effect on 1 March.

About $85bn in across-the-board cuts for this year are divided roughly in half between military and domestic programmes.

The cuts took effect after Democrats and Republicans failed to agree to another plan to cut spending and reduce the US budget deficit.

The Pentagon had previously announced layoffs of 46,000 temporary employees in response to the budget pressures.

The Air Force says the aircraft stand-down is the result of cuts to the Air Combat Command's operations and maintenance account. The budget cuts have forced the service to reduce its flying by about 45,000 training hours.

Some affected units will stand down after current deployments, but the first units will be grounded on Tuesday 9 April.

A combat command spokesman said the Air Force will shift those units' focus to ground-based training exercises to maintain basic skills and aircraft knowledge.

Exceptions would be made for aircraft about to deploy to Afghanistan, as well as those poised to respond in North Africa, including Mali, Gen Philip Breedlove, commander of US Air Forces, said in March.

"The current situation means we're accepting the risk that combat airpower may not be ready to respond immediately to new contingencies as they occur,'' Gen Hostage said in a statement on Tuesday.