Hagel said he has told Pentagon officials, including leaders of the military services, to "identify all employees whose activities fall under these categories." He said civilian workers should stand by for further word this weekend.
In remarks to reporters, Robert Hale, the Pentagon's budget chief, said he did not yet know the exact number of civilians who would be brought back to work but that it would be "90 percent plus." He said there are about 350,000 civilians on furlough.
Hale said he hoped that a "substantial number" could be returned to work on Monday but that an exact timetable was not available.
In a rare Saturday session — and an even rarer showing of bipartisanship — the House voted 407-0 to pass a bill to provide furloughed workers back pay. The Obama administration supports the retroactive pay bill and Senate Majority Leader Harry Reid, D-Nev., said he expects the Democratic-led Senate to pass it.
Even a bill that passed without opposition evoked partisan rhetoric.
"Someone try to explain to the American people today that Republicans decided to shut down government on Oct. 1, and on Oct. 5, they decided to pay all those workers, those 800,000 workers that they told, 'Don't come in to work,'" said Rep. Xavier Becerra, D-Calif. "If it weren't so serious it really would be absurd."
House Majority Leader Eric Cantor, R-Va., noted that many House Democrats supported back pay for federal workers but opposed reopening other selected parts of the government.
The standoff is playing out as an even bigger financial crisis looms. The Treasury Department says the federal government will reach the limit of its authority to borrow money on Oct. 17. If Congress doesn't raise the debt limit, the U.S. will default on its obligations for the first time, triggering what many economists say would be an economic catastrophe.