The Senate passed its version of a $675 billion appropriations bill Thursday to fund the Pentagon in fiscal 2019, setting up negotiations with the House on a final spending plan.

The proposal represents the biggest hike in defense funding in about 15 years, but now must be reconciled by a conference committee with a similar $675 billion bill passed by the House in June. The Senate bill was passed as part of a minibus appropriations bill that included the departments of Education, Labor, and Health and Human Services.

Congress has about a month to negotiate a final compromise on appropriations, vote on it and send it to President Trump for his signature before the end of the fiscal year on Sept. 30.

Otherwise, lawmakers may be faced with passing another stopgap budget measure, which are loathed by Pentagon planners and have been used repeatedly in past years due to partisan impasses.

“We would like to go to conference as soon as we can with the House on the bills coupled together,” said Sen. Richard Shelby, R-Ala., the Senate Appropriations chairman. “We need the House to get back here.”

The Senate bill includes $607 billion in the Pentagon base budget and $68 billion for overseas contingency operations. It sets spending totals for aircraft, ships and troops for fiscal 2019, and represents the final installment of Congress’ two-year budget deal aimed at bolstering and rebuilding the military.

The Navy would get $24 billion for construction of 13 new ships, including two littoral combat ships, despite opposition from the White House over more than a single purchase.

The Air Force would be able to buy 89 F-35 joint strike fighters, an increase over the Pentagon’s request of 77. It would also receive $300 million to purchase a new light attack aircraft, as well as $375 million to develop a new battlefield surveillance system.

Getting the military its annual funding on time this year would be a major accomplishment. Congress has handed the Pentagon numerous continuing resolutions nearly every year for the past decade that have frozen funding levels, caused major headaches for military planners, and contributed to wide-ranging readiness issues among the services.

Sen. Jim Inhofe, R-Okla., who is leading the Senate Armed Services Committee, said he is confident lawmakers will make the fiscal year deadline.

“I’m so confident of that because of the trauma that that would bring,” Inhofe said.