Thailand's government is in talks with US drugmaker Merck & Co to purchase 200,000 courses of the company's experimental antiviral pill for Covid-19 treatment, according to a Thai official.

Somsak Akksilp, director-general of the Department of Medical Services, told Reuters that Thailand is currently working on a purchasing agreement for the antiviral drug, known as molnupiravir.

"We are now working on a purchasing agreement with Merck that is expected to be completed by this week ... we have pre-booked 200,000 courses," Somsak said

He said the pills could arrive as soon as December, though the deal would be subject to the pills' approval by both the United States Food and Drug Administration and the Thai regulator.