Sen. John McCain (R-Ariz.) greets Army color guards after he was presented with the Outstanding Civilian Service Medal during a special Twilight Tattoo on Nov. 14 at Fort Myer in Arlington. (Alex Wong/Getty Images)

The Senate unanimously passed a nearly $700 billion defense authorization bill Thursday, sending the measure to the president's desk despite lingering uncertainty over whether Congress will actually be able to pay for the Pentagon programs it outlined.

The Senate's decision to agree to the measure without a roll-call vote marks a departure from years past, when lawmakers fought bitterly over how to prioritize funding for various Pentagon programs and military operations under a budget still subject to caps Congress imposed on itself in 2011. Congress is facing a mid-December deadline to fund the federal government into next year, and the defense bill exceeds budget caps by about $85 billion.

But lawmakers appeared to put those concerns aside in crafting next year's defense bill, which Republicans cheered as a long-needed investment in the military and Democrats promoted as good policy, even if Congress may not be able to come up with enough funds to put it into practice.

"The support demonstrates that large majorities of both the House and the Senate agree that, based on strategic requirements, this is the defense budget our nation needs," Sen. John McCain (R-Ariz.), chairman of the Senate Armed Services Committee, said after the bill's passage. He encouraged President Trump to sign the measure to "acknowledge that this is the level of defense spending necessary to meet current threats, prepare for the challenges of an increasingly dangerous world, and keep faith with our men and women in uniform."

The bill outlines about $26 billion more for military operations and Pentagon programs than Trump had asked Congress to budget. It also nearly doubles the troop increases Trump had envisioned in his request, creating a total of almost 20,000 new service member positions. The bill commits more money for key aircraft and vessels as well — investments lawmakers argue are vital to save decaying fleets and provide service members with enough training to perform their jobs safely.

Earlier this week, the House passed the same measure by a vote of 365 to 70.

The strong bipartisan coalitions that formed around the defense bill are splintering as Democrats and Republicans turn to the more difficult debate of how to pay for its contents. On Thursday, the Senate Armed Services Committee's ranking Democrat stressed that the GOP's plans for tax reform were worsening an already critical problem of ignoring costs that would "come due" while trying to make needed military investments.

"We knew these costs were coming and we're ignoring them until they come due," said Sen. Jack Reed (R.I.). "We're ignoring them for the benefit of these tax cuts."