Hundreds of thousands of federal workers across the country are not being paid as Democrats and Republicans in Washington squabble over the national budget, leaving some families struggling to meet their costs.

Payments to some of America's poorest people, including the Supplemental Nutrition Assistance Program (SNAP) -- known colloquially as food stamps -- are also due to expire in the coming days if no agreement is reached.

That is set to put extra pressure on food banks, which typically offer free or low-cost produce to people who cannot otherwise afford to buy it.

Governor Gavin Newsom said he would be activating the Guard to do the kind of food bank work they performed during the Covid pandemic, when they helped serve millions of meals.

Newsom, a Democrat who battled President Donald Trump's order to deploy the National Guard to support immigration raids, said he was also fast-tracking $80 million of state support to help feed those in need.

"Trump's failure isn't abstract -- it's literally taking food out of people's mouths," said Newsom, who is expected to seek the Democratic nomination for the White House in 2027.

"Millions of Americans rely on food benefits to feed their families, and while Republicans in Washington drag their feet... California is working to ensure (food stamp) recipients don't go hungry while food prices are spiking."

Nationally, the program feeds more than 42 million people, with roughly 5.5 million in California alone.

The federal government shutdown, now in its fourth week, is the second longest in history, with no end to the stalemate in sight.

The National Guard is a state-based military reserve force, made up largely of people who serve part-time while holding civilian jobs or conducting other activities.

It is routinely mobilized to address emergencies on US soil, typically natural disasters.

In the last few months Trump has sparked fury by federalizing parts of the Guard to deploy troops in Democratic cities including Los Angeles and Washington.