A political row has erupted after Donald Trump claimed Americans hit hard by Hurricane Helene were losing out on emergency relief money because it had been spent on migrants.

The blame game began on Wednesday after US Homeland Security Secretary Alejandro Mayorkas said the Federal Emergency Management Agency (Fema), which he oversees, was short on cash for the rest of hurricane season.

Trump and his allies expressed outrage that the agency had spent over $640m (£487m) on housing migrants. But US officials said that money was allocated through a totally different funding pot to disaster relief.

The White House has called Trump’s claims “poison” and accused his fellow Republicans of spreading “bald-faced lies” about the storm response.

With less than a month to go before the White House election, Trump and the Democratic nominee Kamala Harris are neck and neck in the handful of swing states, such as storm-hit North Carolina and Georgia, that will decide the vote.

The deadliest mainland US hurricane since Katrina in 2005, Helene tore through the south-east last week, claiming at least 225 lives and leaving hundreds more missing.

Both Trump and Vice-President Harris have made trips to some of the affected states.

At an event in Evans, Georgia, on Friday, Trump said: “A lot of the money that was supposed to go to Georgia and supposed to go to North Carolina and all of the others is going and has gone already.

“It’s been gone for people that came into the country illegally, and nobody has ever seen anything like that. That’s a shame.”

Fema did receive a budget from Congress – $640m in the last fiscal year – to provide housing to immigrants applying for US citizenship.

But the cash came via a federal immigration agency, Customs and Border Protection.

It was spent through Fema’s Shelter and Services Program (SSP) and is a separate pot of money to the agency’s Disaster Relief Fund of nearly $20bn, which is used to respond to hurricanes and other natural disasters.

Fema’s disaster relief budget for the year expired at the end of September and the agency is currently running on temporary funding while Congress negotiates a new annual budget.

The agency has responded to Trump’s claim with a dedicated fact-check page, and a statement from the Department of Homeland Security.

“This is false,” Fema said in a statement. “No money is being diverted from disaster response needs.”

So far, more than $45m has been given to communities affected by Hurricane Helene, said the agency.

Fema has also shipped over 11.5m meals and 12.6m litres of water in the aftermath of Helene, said Vice-President Harris on Friday, adding that more than 5,600 federal personnel were on the ground.

But Trump’s son, Donald Trump Jr, posted on X, formerly Twitter, on Thursday that it was “madness” for billions of dollars in foreign aid to be sent to Ukraine, instead of to American citizens who had lost everything in the storm.

Meanwhile, critics of Trump have pointed out that when he was president back in 2019, $155m was transferred from Fema’s operating budget to fund deportations of migrants to Mexico.