California’s local and state-wide transportation agencies are still relying on President Donald Trump to provide federal funding to run and build their transit operations, despite Republicans’ resistance to funding high-speed rail.

According to Southern California Public Radio (SCPR), last month the Federal Transit Administration delayed a decision on whether it would approve a $650 million federal grant meant to convert the Bay Area railway system, Caltrain, from diesel to electric. The electrification is necessary to complete the last, northern leg of the California High-Speed Rail Authority’s effort to link San Francisco with Los Angeles via bullet train.

SCPR reported the move “rattled some officials here” in the Southern California region.

Last year, approximately 18 percent of L.A. Metro’s budget came from federal funds, and reportedly paid for half of the funds for the new Purple Line Subway and Regional Connector.

However, the high-speed rail project has imperiled federal funding for local projects more broadly.

Last month, California’s House Republicans wrote a letter asking Trump to block the pending $650 million federal grant for Caltrain until an audit of the project’s finances is completed.

Rep. Jeff Denham (R-CA), who serves as Chairman of the House Railroads, Pipelines and Hazardous Materials Subcommittee, issued a statement following a report showing the initial segment of the high-speed rail would come in massively over budget and behind schedule:

Despite past issues with funding this boondoggle, we were repeatedly assured in an August field hearing that construction costs were under control. They continue to reaffirm my belief that this is a huge waste of taxpayer dollars. I will continue to fight against any further federal funding of this project. They can expect an audit and oversight hearing in the near future.

L.A. Metro CEO Phil Washington told SCPR that he is still optimistic that his agency will continue to receive federal funding, saying “We think that federal funds will come our way because we have invested in ourselves.”

However, other Metro officials are reportedly doubtful about future funding.

Last week, Dan Walters wrote a column in the Sacramento Bee arguing that the high-speed rail, Gov. “Brown’s pet project,” could be dead.

Follow Adelle Nazarian on Twitter and Periscope @AdelleNaz