The ministry said in addition to supplying neighbouring countries, India would also give it to other nations "badly affected by the pandemic".

On Monday, Donald Trump said the US could "retaliate" if India didn't release stocks of the drug, which he has called a "game-changer" in the fight against Covid-19.

Hydroxychloroquine is very similar to Chloroquine, one of the oldest and best-known anti-malarial drugs.

But it remains unclear whether the drug can actually work against coronavirus. Many virologists and infectious disease experts have cautioned that the excitement over hydroxychloroquine is premature and the drug has not been properly tested.