Grocery bags with food from WIC sit in a shopping cart in Jackson, Mississippi in 2013.

The WIC food assistance program has received a $300 million lifeline to keep operating for a few more weeks during the government shutdown, according to a source familiar with the funding transfer.

The money comes from leftover tariff revenue from the past fiscal year that typically is used to fund child nutrition programs. The US Department of Agriculture told congressional staffers last week about the transfer, according to the source.

WIC, which provides food assistance and services to nearly 7 million pregnant women, new mothers and young children, had been in danger of running out of money by the middle of the month. But the Trump administration announced last week that it would shift tariff revenue to the program.

The infusion should be enough to keep WIC afloat for the rest of the month, said Ali Hard, policy director at the National WIC Association. But if the shutdown continues into November, the benefits could once again be at risk.

Still, Mississippi has taken the unusual step of instituting a wait list, prioritizing pregnant women, breastfeeding mothers and high-risk infants for benefits, according to the state Department of Health.

At least two Native American tribes have also set up wait lists, according to a source familiar with the program.