President Donald Trump said Thursday he directed the Food and Drug Administration to investigate whether an existing drug for malaria can be used to treat the coronavirus.

There are no proven therapies for the COVID-19 virus, which has rapidly grown into a pandemic. U.S. health officials say a vaccine ready for public use could take 12 to 18 months. But some scientists have said the anti-malaria drug chloroquine could be a treatment for the virus.

It is important "not to provide false hope," FDA Commissioner Stephen Hahn said at the White House's daily press briefing on the coronavirus. But Trump has "asked us to be aggressive" and "break through exciting, life-saving treatment, and we're doing that at the FDA," Hahn said.

The World Health Organization, however, said last month that there is "no proof" the drug is effective in treating the coronavirus.

Trump claimed that the U.S. would be able to make the anti-malaria drug available "almost immediately" and that "it's been approved." But multiple outlets reported minutes later that the FDA had not approved chloroquine for use in treating the coronavirus.

The FDA did not immediately respond to CNBC's request for comment.

The announcement at the briefing Thursday came hours after Treasury Secretary Steven Mnuchin said the White House's massive economic stimulus proposal would include $500 billion for direct payments to Americans.