The US Congress on Thursday approved a stopgap measure to avert a damaging election-year government shutdown, extending funding for several key federal agencies past a weekend deadline.

Five months into the fiscal year, Congress still has not approved the 12 annual spending bills that make up the federal budget, which were facing deadlines of midnight on Friday night and March 8 to keep the lights on.

The Republican-led House and Democratic Senate approved a short-term "continuing resolution" extending the deadline for the first six bills until March 8 and making March 22 the cut-off for the remaining six.

Money for agriculture, science, veterans' programs, transport and housing had been due to run out first, potentially hitting food safety inspections, air traffic controllers' pay and numerous other important functions.

A full shutdown would have come a week later -- a day after President Joe Biden's March 7 State of the Union address -- leaving defense, border security, Congress and many other departments and agencies unable to operate.

But the fourth stopgap funding bill approved under this Congress -- and the third under House Speaker Mike Johnson's leadership -- only gives lawmakers a few extra days to get back on track.

Johnson has been struggling to corral a razor-thin majority, walking a tightrope between the demands of his own right flank and more moderate Republicans.

- 'Working together' -

All but two Democrats in the House voted yes to the continuing resolution but 97 Republicans voted against.

It passed the upper chamber in a 77-13 evening vote and will now make its way to Biden's desk in time to keep the wheels of government turning.

"This is a short-term fix -- not a long-term solution," Biden said in a statement, calling on Republicans to pass full-year funding bills as well as new military aid for Ukraine, which has been blocked by conservative hardliners in the House.

While moderates consider shutdowns politically disastrous, and a threat to Republican chances of hanging onto the House and retaking the Senate in November, right-wingers in safe seats are more inclined to spoil for a fight.

Conservatives have been pushing to eliminate Homeland Security Secretary Alejandro Mayorkas's salary, block travel costs for armed forces personnel seeking abortions and defund parts of Biden's climate agenda -- all red lines for Democrats.

Biden cut a deal with Republicans last year mandating tens of billions of dollars in automatic cuts if lawmakers fail to pass full-year spending bills by April.

The hard-right, 40-member House Freedom Caucus, angered by entreaties from the leadership to accept compromise on its priorities, has made no secret of the fact that it would be happy for that ax to fall.

"We can't let the swamp dictate the terms," Texas congressman Chip Roy posted on X.

Biden called a rare Oval Office meeting for congressional leaders on Tuesday to jolt them into striking a deal on the budget, and to unblock vital aid for Ukraine that is also stalled by infighting among Republicans.

"If our House Republican colleagues of goodwill want to do the right thing, they must accept a fundamental truth about divided government: Republicans cannot pass a bill without Democratic support," Senate Majority Leader Chuck Schumer said.

"It takes both sides working together -- and ignoring the extremes of the hard right -- to get anything done."