WASHINGTON — The Senate Armed Services Committee's top Democrat is pessimistic the 2016 National Defense Authorization Act will be finalized before the end of the month, and money remains the toughest issue in negotiations, he told reporters Thursday.

The "Big Four" Senate and House Armed Services Committee leaders, in their second week of negotiations, are racing against the clock. The Senate is scheduled to recess at the end of the month, though the Senate's GOP leadership plans to quickly wrap up a stop-gap resolution to fund government past the close of the fiscal year Sept. 30, and adjourn earlier.

"I think it's getting increasingly difficult to get anything done, just in terms of the mechanics of the floor, before the recess," said Senate Armed Services Ranking Member Jack Reed, D-R.I.

"I just think more the procedure of getting it done, getting it finalized, getting it approved by House Rules [Committee] and to the floor, it's probably unlikely," Reed said of the NDAA.

The Senate spending and policy bills support the president's budget, while the House bills redirect $18 billion in the Overseas Contingency Operations (OCO) account — which is exempt from statutory budget caps — for unrequested troops and equipment. The gambit spearheaded by House Republicans would leave operations in Afghanistan unfunded to force the next president to request Congress pass supplemental defense spending.

"The biggest issue has always been how do you deal with the top-line," Reed said. "The House has approached it, you limit OCO funding for several months, versus what we did in the Senate. I think that's still a significant issue."

Though Reed did not mention it, President Obama has threatened to veto the House and Senate versions of the bills — the House bill over its unorthodox treatment of OCO, and the Senate bill over its acquisition reform provisions and limits it would place on the closure of the Guantanamo military detainment facility in Cuba.

Asked whether the conferees had reconciled with House bill’s approach to OCO, Senate Armed Services Committee Chairman John McCain, R-Ariz., said, "We haven’t finished our discussions; There’s no consensus yet.

Though earlier in the week, McCain said lawmakers aim to "have this thing done by next week," and that "some" of the marquee issues had been resolved, McCain on Thursday declined to say whether acquisition reform measures were among them.

"I can't say until the discussions are complete, and the discussions are not complete," he said.

Sen. Ben Cardin, ranking member of the Senate Foreign Relations Committee, said Monday he was pessimistic the NDAA could be resolved before the post-Nov. 8 election "lame duck" session.

"There's so many issues last time [I checked], unrelated to my issues, that it didn't seem that they'd be able to resolve that, and the Republicans are very anxious to get out of here," Cardin said.

"I would be happy to stay here as long as we can to work out the NDAA, to work out a longer term budget deal," he said. "There are a lot of things to get done, and I would stay here to get it done. I just don't see the Republicans doing it."

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