“President Trump has chosen to take away food from people all around this country,” Healey, a Democrat, said during a briefing on Friday at Nubian Markets in Roxbury. “That’s going to mean that 1 million people in Massachusetts are not going to have their food benefits starting next week.”

The USDA said its contingency funds “are not legally available” to cover regular benefits, according to a memo obtained by Axios. The contingency fund can only be used after money has been appropriated for SNAP but is insufficient to cover the total cost of benefits, the memo said, adding that such funds are reserved for emergencies such as natural disasters. Democrats disputed that interpretation.

Massachusetts residents receive about $240 million a month in SNAP benefits. About one-third of recipients in Massachusetts are children, 31 percent have disabilities, and 26 percent are seniors, Healey noted.

Soraya Harley, a grandparent who uses SNAP benefits to feed her grandchildren, said losing the benefits for even one month would be “devastating,” noting that grocery prices continue to rise.

“My grandchildren need proper nutrition to stay healthy and focus in school,” Harley said at the Nubian Markets event. “This program is not just a line in a budget, it’s a lifeline for families like mine.”

Asked whether Massachusetts could use any of its own money, such as the “rainy day” fund that had more than $8 billion at the end of June, for food aid, Healey said the state “cannot begin” to cover the federal shortfall.

For now, the 13 United Way organizations in Massachusetts are launching a United Response Fund, and Healey appealed to people to contribute to “help feed our families, our seniors, our kids, our neighbors with disabilities.”

In New Hampshire, officials on Friday announced plans to provide $2 million of public funding for mobile food pantries that will be open to SNAP recipients. Addressing the looming loss of benefits, Governor Kelly A. Ayotte said, “Politicians in Washington must get their act together and reopen the federal government.”

In Vermont, state officials are formulating a plan to cover missing federal funds with state money for SNAP and another program that assists with home heating bills.

Asked about the looming cutoff during a briefing Friday, Director of the National Economic Council Kevin Hassett implied that Trump’s budget director, Russell Vought, was working on an interim solution.

Vought’s office and the USDA did not return requests for comment.

The SNAP program serves more than 40 million people nationwide, but it was already facing pressure from the weakening labor market and changes in the Republican “Big Beautiful Bill” passed in July. The bill added new paperwork and employment requirements that could exclude 150,00 people in Massachusetts from receiving SNAP benefits over the next year, according to Healey.

SNAP recipients receive money on prepaid cards that they can use for groceries. Healey warned of the economic impact from a pause in funding on the estimated 5,500 grocery stores and farms where SNAP money is used in Massachusetts.

Marty Martinez, chief executive of United Way of Massachusetts Bay, said at the Nubian Markets event that organizations dedicated to food security will be able to apply for money contributed to the response fund.

“To be very clear, our goal is to raise money,” said Martinez, whose organization focuses on Eastern Massachusetts. He did not specify a fund-raising goal, saying the organization is trying to raise as much money as possible.

Jennifer Lemmerman, chief policy officer at Project Bread, said the organization had been “hearing something new” in the calls it’s received from people seeking help: “Fear.”

Senator Edward J. Markey and Representative Ayanna Pressley spoke at Project Bread in East Boston to highlight the efforts of local food pantries and food banks to support communities impacted by the Republican shutdown on Friday. David L Ryan/ Globe Staff

At a separate news conference organized by Senator Ed Markey and Representative Ayanna Pressley, Lemmerman said recipients were confused about what changes could be coming and social workers wanted to know what local resources might be available.

“Emergency food providers are already stretched beyond capacity and they cannot absorb the flow,” Lemmerman said. “Let’s be clear: This is not an inevitable consequence of the shutdown; it is a political choice, and one that could be reversed today.”

Rhode Island’s two Democratic senators, Sheldon Whitehouse and Jack Reed, have also blamed the Trump administration.

The two lawmakers joined 43 of their Senate colleagues in a letter this week urging the Trump administration “not to delay or deny SNAP funds to states.”

“Americans are already struggling with the rising cost of groceries, and they cannot afford a sudden lapse in grocery assistance,” they wrote.

Material from the Associated Press was included in this report. Travis Andersen of the Globe staff also contributed.

Katie Muchnick can be reached at katie.muchnick@globe.com. Anjali Huynh can be reached at anjali.huynh@globe.com.