LANGLEY AIR FORCE BASE, Virginia (Reuters) - Defense Secretary Robert Gates named new top civilian and military leaders for the U.S. Air Force on Monday as part of a shake-up triggered by mistakes in managing America’s nuclear arsenal.

Senior Pentagon official Michael Donley (L) and Gen. Norton Schwartz in a combination image. Defense Secretary Robert Gates on Monday recommended Donley to be secretary of the U.S. Air Force in a shake-up triggered by mistakes in handling nuclear weapons and parts. Gates also said he recommended Schwartz as the new Air Force chief of staff. REUTERS/Department of Defense/Handout

He also halted cuts to the size of the Air Force to ease the stress from operations in Iraq and Afghanistan, noting the Army is not the only force under pressure after years of war.

Gates chose Gen. Norton Schwartz, a cargo aircraft pilot with special operations experience, as Air Force chief -- a pick that signals the Pentagon wants the force to focus on supporting the two wars, U.S. officials said.

Gates also selected senior Pentagon official Michael Donley to be secretary of the Air Force, the top civilian official.

President George W. Bush planned to nominate Donley, who would serve as acting secretary beginning June 21 until his appointment is confirmed by the U.S. Senate, White House spokeswoman Dana Perino said.

If confirmed by the U.S. Senate, Schwartz would be the first Air Force chief of staff not to have served as a fighter or bomber pilot, an Air Force spokeswoman said.

Gates’ recommendations to Bush came after the Pentagon chief last week forced Air Force Secretary Michael Wynne and Chief of Staff Gen. Michael Moseley to resign over errors in the handling of nuclear weapons and parts.

In announcing the resignations, Gates said two incidents -- the shipment of nuclear missile fuses to Taiwan and the cross-country flight by an Air Force bomber wrongly armed with nuclear weapons -- exposed a systemic problem in the Air Force and an erosion of nuclear standards.

“There is simply no room for error in this mission,” Gates told Air Force officers at Langley Air Force Base in Virginia on Monday. “Nor is there, unfortunately, any room for second chances, especially when serious questions about the safety and security of our nuclear arsenal have been raised in the minds of the American people and international partners.”

“I am confident that Mike Donley, General Schwartz and the new Air Force leadership team have the qualifications, skill and commitment to excellence necessary to guide the Air Force through this transition and beyond,” Gates said.

CUTBACKS HALTED

Gates cited missions the Air Force has been conducting and noted, to vigorous nods from officers in the audience, that the force has been deployed for 17 years, since the first Gulf War.

In response to that stress, Gates said he would immediately halt an ongoing reduction in the size of the Air Force. The Air Force was expected to shrink to 316,000 service members by the end of next year, down from 356,000, a Langley spokesman said.

The choice of Schwartz, who commands the military headquarters responsible for transporting troops and equipment around the world, marks a significant shift for a force typically led by fighter jet or bomber pilots.

The Air Force and Pentagon have been at odds over mission priorities and weapons systems. Gates, for example, has noted the Air Force’s top-of-the-line F-22 fighter jet has not flown a single mission in either Iraq or Afghanistan. Still, it remains a priority among some senior Air Force generals.

Gates also has voiced frustration with the Air Force’s reluctance to take pilots off missions in the war zone that could more effectively and safely be done by drones.

“There must be focus on the wars we are in as well as on building future capabilities,” Gates said at Langley. “It is a matter of balance.”

Schwartz, who had intended to retire before being nominated as Air Force chief, also has held a series of jobs working closely with other military services and his appointment may signal that Gates wants to see the Air Force take that approach more broadly.

Donley, who would become the top civilian in charge of the Air Force, is currently director of administration and management for the Department of Defense.

He has previously served as both assistant secretary of the Air Force and as acting secretary of the Air Force.