Gates spent several hours touring the base, called the "Gateway to the Air Force," where an estimated 600 servicemen graduate from basic training each week.

Lackland officials briefed Gates on measures to extend the six-and-a-half-week basic training program by two weeks, the American Forces Press Service said. The extension provides recruits with additional weapons training as well as field medicine practices.

"It takes uncommon perseverance to make it through basic training, especially in the Texas heat, just as it takes uncommon patriotism to make the decision to join the military in a time of war," he said.

Gates praised the work of the 6,000 Air Force servicemen who work in non-combat military operations, such as provincial reconstruction and ordnance clearing.

"Put simply, without the Air Force's contributions in the skies and, in many cases, on the ground, America's war effort would simply grind to a halt," the secretary said.

Gates received his commission from the Air Force at Lackland in 1967.