The U.S. Congress began moving to extend Friday's budget deadline until May 5 and is expected to pass legislation allowing more time to finalize a spending deal to fund the federal government through September and avoid a shutdown.
House Appropriations Committee Chairman Rodney Frelinghuysen introduced a bill late on Wednesday night to fund government operations at current levels for one more week, giving leading Republicans and Democrats time to finish negotiations on a spending plan for the rest of the fiscal year ending on Sept. 30.
Without the congressional extension or a longer-term funding bill, federal agencies will run out of money by midnight Friday, likely triggering abrupt layoffs of hundreds of thousands of federal government workers until funding resumes.
The last government shutdown, in 2013, lasted for 17 days, and many lawmakers are nervous at the prospect of another.
"I am optimistic that a final funding package will be completed soon," Frelinghuysen, a New Jersey Republican, said in a statement.
Negotiators spent Wednesday racing against the clock to resolve remaining disputes in the massive spending bill amid talks that have already handed Democrats at least two major victories despite Republican control of Congress.
President Donald Trump, also a Republican, gave in to Democratic demands that the spending bill not include money to start building the wall he wants to erect on the U.S.-Mexico border. His administration also agreed to continue funding for a major component of the Affordable Care Act, commonly known as Obamacare, despite vows to end the program.
It remained unclear whether Republicans would prevail in their effort to significantly increase defense spending without similar increases to other domestic programs. Trump has proposed a $30 billion spending boost for the Pentagon for the rest of this fiscal year.
Such funding disputes could resurface later in spending bills for the next fiscal year starting in October.
Other disagreements must also still be ironed out in the current plan, including funding to make a healthcare program for coal miners permanent and to plug a gap in Puerto Rico's Medicaid program, the government health insurance program for the poor.
Additional "riders" on other issues could also be tucked into the legislation, which must pass both the U.S. House of Representatives and the Senate.
Although Republicans control both chambers of Congress, they hold just 52 seats in the Senate and will need support from some Democrats to win the 60 votes needed there to pass the bill. (Additional reporting by Susan Cornwell and Amanda Becker in Washington and Caroline Humer in New York; Editing by Peter Cooney and Lisa Von Ahn)