A US judge has ordered the Trump administration to fully fund the federal Supplemental Nutrition Assistance Program (SNAP), also known as food stamps, and accused the administration of withholding the food aid "for political reasons".

Judge John McConnell said in his order on Thursday that without the aid, "16 million children are immediately at risk of going hungry".

The programme is used by about 42 million, or about 1 in 8, in America and helps those with low income afford groceries.

The administration at first planned to halt its funding entirely this month due to the government shutdown, which is now the longest in US history, but had been ordered to doll out at least partial payment.

The judge, who is based in Rhode Island, also criticised President Donald Trump for saying that benefits would only be distributed after the government shutdown ends, calling it "an intent to defy the court order".

He granted a request from several local governments and non-profit groups that asked that the government provide full food benefits, rather than the 65% that had been ordered to be paid out this month.

Judge McConnell, who was appointed by President Barack Obama, ordered that benefits be paid by Friday, adding that any further delay would be "simply unacceptable".

"This should never happen in America," he continued.

He added that the government "knew there would be a long delay in paying [partial] SNAP benefits and failed to consider the harms individuals who rely on those benefits would suffer".

The White House has said it plans to appeal the ruling. After Trump had earlier vowed to withhold aid until the shutdown ends, his spokeswoman clarified that the administration would comply with the judge's order.

Trump, reacting to the ruling at a dinner with Central Asian leaders at the White House, blamed Democrats for the shutdown and said that there are too many undeserving people using the Snap programme.

"This was meant for people that had real problems. In many cases, people who were down and out," Trump said.

"It wasn't meant for people that say, 'Well I don't want to work.'"

Sitting next to Trump, Vice-President JD Vance chimed in and accused the judge of "telling the president how he has to triage the situation".

"The American people are unfortunately about to start suffering some very real consequences from the shutdown," Vance added, noting the issues with Snap and also airports.

Democracy Forward, an advocacy group which brought the lawsuit, praised the judge's ruling as a "major victory".

"The court could not be more clear — the Trump-Vance administration must stop playing politics with people's lives by delaying Snap payments they are obligated to issue," Democracy Forward President Skye Perryman said in a statement.

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More than 42 million Americans received Snap benefits, however the programme has been in limbo during the more-than-month-long shutdown.

While individual US states administer the benefits, the programme relies on money from the federal government, which has been unfunded and shut down since 1 October.

Late last month, the US Department of Agriculture (USDA), which runs Snap, said it would not distribute food-assistance funds entirely starting 01 November because of the shutdown, saying: "The well has run dry."

Half the states and the District of Columbia sued the administration over the food-aid freeze and argued that they had a legal obligation to keep the programme running in their jurisdictions.

Federal judges in Massachusetts and Rhode Island ruled that the administration needs to use $5.25bn (£4bn) in emergency funds to make at least partial payments to Americans.

Snap costs about $8bn per month and allows many low-income Americans to buy groceries. It provides them reloadable debit cards that they can use to buy food.

A family of four on average receives $715 per month, which breaks down to a little less than $6 per day, per person.

Amid the uncertainty over Snap funding, local governments have been helping direct recipients to charity food pantries, which have been holding emergency drives.

Cost-saving recipes have also gone viral online, as Americans search for ways to stretch their budget.