(Evan Vucci/AP) - Defense Secretary Chuck Hagel. Defense Secretary Chuck Hagel  (Evan Vucci/AP)

Secretary of Defense Chuck Hagel said Tuesday that the Pentagon will reduce the the number of furlough days faced by the department’s civilian workers from 11 days to six.

Approximately 640,000 civilian defense workers are entering their fifth week of furloughs under the sequester.

“I regret the difficulties they and their families had to face during this furlough period,” Hagel wrote in a memo Tuesday announcing the reduction

Hagel said a combination of congressional funding and Pentagon “budget management efforts” allowed the reduction from the 11 days he announced in mid-May.

“Since then, Congress has approved most of a large reprogramming request that we submitted in mid-May, giving us flexibility to move funds across accounts,” Hagel wrote in his memo, which was addressed to senior military commanders. “The military services have been aggressive in identifying ways to hold down costs, and we have been successful in shifting savings (including furlough savings) to meet our highest priority needs.”

But the defense secretary warned that despite the improved situation, “this is a military whose readiness remains seriously degraded as we head toward the budgetary uncertainties” of the coming fiscal year.

The reduction in the number of furlough days means most employees will have met their furlough requirements by Aug.17, according to Hagel’s memo. All employees who are not exempt from furloughs must meet the six-day requirement before the end of the fiscal year.

The reduction was first reported by the Associated Press.

One of the largest labor unions representing civilian defense workers applauded the decision in a statement Tuesday.

“AFGE has argued from the start that the Department of Defense furloughs were always the worst possible way for the department to absorb sequestration’s cuts,” said American Federation of Government Employees President J. David Cox. “The secretary’s announcement suggests that he has finally realized that furloughs are costly in terms of dollars, readiness and morale.”

To connect with Josh Hicks, follow his Twitter feed, friend his Facebook page or e-mail josh.hicks@washpost.comFor more federal news, visit The Federal Eye, The Fed Page and Post Politics. E-mail federalworker@washpost.com with news tips and other suggestions.

This post has been updated.