Donald Trump made an unfounded claim that hospitals have been stealing masks, despite US states demanding more medical supplies to manage the coronavirus pandemic.

As US cases of the coronavirus neared 140,000 on Sunday, the president told reporters assembled at the White House that “something was going on” with the supplies of medical masks.

“They’ve been delivering — for years — 10 to 20,000 masks, ok. It’s a New York hospital, it’s packed all the time,” said Mr Trump as he suggested the current demand for supplies was suspicious.

“How do you go from 10 to 20 to 300,000? 10 to 20,000 masks, to 300,000 — even though this is different? Something is going on, and you ought to look into it as reporters. Are they going out the back door?”

Asked to explain by a reporter what he meant, the president suggested that frontline hospital staff were stealing the equipment.

“I don’t think it’s hoarding, I think it’s maybe worse than hoarding but check it out”, said Mr Trump.

Speaking in the White House Rose Garden, the president called on New York’s leaders to take a look. “I want the people in New York to check, Governor Cuomo, Mayor de Blasio, that when a hospital that’s getting 10,000 masks goes to 300,000 masks during the same period, people should check that because there’s something going on.”

Mr Trump did not provide evidence to support his claims on Sunday. It comes two days after New York governor, Andrew Cuomo, announced that state police were investigating the theft of medical supplies from some hospitals.

Tension between Mr Trump and Mr Cuomo came to a head last week after the president repeated the claim that states, including New York, had either been hoarding ventilators or were asking for too many.

Mr Cuomo said the president’s comments on ventilator hoarding were “incorrect and grossly uninformed”.

On Sunday night, Joe Biden, who leads the race for the Democratic presidential nomination, said: “This is ridiculous and completely false. Today’s conspiracy mongering from our president is among the most reckless and ignorant moves he has made during this crisis, and there have been many. Lives hang in the balance.”