WASHINGTON — A fight over where to relocate the FBI's headquarters ground the Senate appropriations process to a halt on Thursday — a setback for lawmakers working to avert a government shutdown by the Sept. 30 deadline. The Senate Appropriations Committee had been scheduled to pass one of its 12 appropriations bills and send it to the full Senate. But Chair Susan Collins, R-Maine, was forced to recess the committee meeting after a Democratic amendment to block the Trump administration frommoving the FBI headquartersto the Ronald Reagan Building in Washington surprisingly passed. The amendment, offered by Sen. Chris Van Hollen, D-Md., would bar the administration from using federal dollars to move the FBI's headquarters in downtown Washington to a site other than in Greenbelt, Maryland, in the suburbs just outside Washington. The Appropriations Committee passed the amendment during a markup of the Commerce, Justice, Science, and Related Agencies appropriation bill in a 15-14 vote, with just one Republican — Lisa Murkowski of Alaska — crossing the aisle and joining all Democrats in voting yes. "This is good news for the men and women in the FBI because the Greenbelt site was selected after years of competition to pick the site that best met the security and mission requirements of the FBI," Van Hollen told NBC News after the amendment vote. Passage of the amendment is "an important step" and a "very important signal," he said. But Republicans on the panel, worried about the FBI provision and how President Donald Trump might respond, began announcing they were switching their votes on the full bill from yes to no. Instead of letting the bill fail in committee, Collins recessed the meeting to give senators time to figure out a path. Senators went home for the week Thursday and said they'd revisit the issue when they return next week. After recessing the meeting, Collins argued that her committee is making progress on appropriations bills on a bipartisan basis. One to fund the Agriculture Department passed 27-0, while another to fund the legislative branch passed 26-1. "We got two of our bills approved today, one unanimously and one with only one dissenting vote. Had the issue of the FBI building not come up, we would have had a third bill with strong bipartisan support," Collins told reporters. Sen. John Kennedy, R-La., an appropriator, explained why he is opposed to the bill with the FBI provision. "The Democrats, with one Republican vote, were able to add an amendment that basically turns upside down the president's decision about where to put the FBI building," Kennedy said. "Now, I know that sounds like inside baseball, but it really is a big deal," he continued. "It's a lot of taxpayer money, and I think that just blew up the process. I think the president is going to be furious." In November 2023, during the Biden administration, the General Services Administration — an agency that manages federal property and buildings — announced Greenbelt as thelocation of the new FBI headquarters. The decision capped ayearslong selection processin which both Virginia and Maryland vied to house the new campus. But this month, the Trump administration reversed that decision and said the new headquarters would instead land at the Ronald Reagan complex in downtown Washington, which FBI Director Kash Patel and other officials described as a cost-effective location that can meet the needs of the agency's workforce. The FBI's current headquarters in the J. Edgar Hoover Building has deteriorated since it opened in the 1970s, requiring either extensive renovations or a whole new campus to be constructed. Murkowski told reporters after the committee meeting that she supports pausing consideration of the bill so she can hear from the FBI why they want to stay in Washington. "We had an opportunity to take a pause, get a little more information about what it is that the administration is seeking to do with the Ronald Reagan Building, because it seems to me that's kind of the blank spot right now," Murkowski told reporters, "So, I think we're going to have that chance." It's not clear when the Appropriations Committee will meet again to restart considering the bill. The Senate panel's markup of the bill is just the first step in a long process to fund federal agencies before money for the government runs out at the end of the fiscal year on Sept. 30.