The US is fast-tracking the anti-malarial drug chloroquine for use as a treatment against the new coronavirus, President Donald Trump said Thursday.

"We're going to be able to make that drug available almost immediately, and that's where the FDA (Food and Drug Administration) has been so great," Trump told reporters. "They've gone through the approval process -- it's been approved. They took it down from many, many months to immediate. So we're going to be able to make that drug available by prescription."

But the FDA Commissioner Stephen Hahn later indicated that, while the drug has not yet been formally approved, access to it was being expanded so that authorities could gather more data.

This is known as "compassionate use."

"If there is an experimental drug that is potentially available, a doctor could ask for that drug to be used in a patient. We have criteria for that and very speedy approval for that," said Hahn.

"As an example, many Americans have read studies and heard media reports about this drug chloroquine, which is an anti-malarial drug. It's already approved, as the president said, for the treatment of malaria as well as an arthritis condition. That's a drug that the president directed us to take a closer look at, as to whether an expanded use approach to that could be done to actually see if that benefits patients."

Chloroquine is a synthetic form of quinine, which has been used to treat malaria since the 1940s. The drug has recently been used to treat coronavirus patients in China and in France, where some researchers said it showed great promise, though scientists agree that only more trials would determine if it really works and is safe.