Anticipating the first wartime change of presidents in 40 years, Defense Secretary Robert Gates said Tuesday he has begun laying the groundwork to enable his successor to manage the wars in Iraq and Afghanistan — and other challenges — from his or her first day in office.

Gates said that over the past two decades it has become more difficult and time consuming to get key officials into Pentagon jobs early in a new administration. Doing it faster will be even more important this time, he said, in light of the complexities of the wars and difficult security issues elsewhere.

"I've been through a lot of these (transitions) and I've seen them up close and I want to see if we can improve on the past," he said. Gates' national security career dates to the Nixon administration and includes the transition in January 1993 from President George H.W. Bush to President Clinton.

"I think it's a real problem and it's gotten worse with every presidential transition over the last 20 or 25 years — how long it takes to get the teams basically in place" at the Pentagon, he added.

Gates said he has asked one of his advisory groups, the Defense Policy Board, to make recommendations this month on what "the new secretary is going to have to know about and be ready to deal with on Day One — obviously Iran, Iraq and Afghanistan," and also budgetary and other issues, he said.

The advisory panel also will recommend to Gates what longer-range issues should be briefed early in the process.

Separately, a senior aide — Michael Donley, the Pentagon management chief who was nominated Monday by President Bush to be the next Air Force secretary — is examining the administrative nuts and bolts of the transition, Gates said.

Gates also said he has told a number of senior Pentagon civilian officials to be prepared to remain in place beyond Inauguration Day, Jan. 20, if requested by the next president, in the interests of continuity during wartime.

He said he was concerned that the next Pentagon chief "doesn't arrive to find that on the civilian side of government he's all alone."

Navy Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, has said he is forming an advisory team of his own to determine what key issues should be discussed first with the next defense secretary. Part of that study is an examination of the nation's vulnerabilities during a presidential transition.

Mullen, who took office last fall, will be one of the key transition figures in January, since his term does not expire with the end of the Bush administration. As joint chiefs chairman he is the main military adviser to the president and the defense secretary.

Gates, who has said he has no intention of staying past the Bush administration, told reporters flying with him from Scott Air Force Base, Ill., to Washington that he favors the idea of having the Republican and Democratic presidential nominees assemble a pool of potential appointees in the arena of national security and homeland defense before the November election so they can be vetted in advance.

In that scenario, the sometimes lengthy background checks that must be performed on candidates for national security positions could be completed before Inauguration Day "so that we don't have empty seats at the Department of Defense at a time we're fighting two wars," Gates said.

Gates said the issue of the national security implications of a presidential transition during wartime came up Tuesday when he met privately with several hundred airmen at Peterson Air Force Base, Colo. Gates visited Peterson and Scott Air Force Base on Tuesday to explain his decision to replace the Air Force's top civilian and uniformed officials. Reporters were not allowed to attend the private session.