Covid infections in Iran surged again Wednesday, hitting a new one-day record for a third straight day and taking total cases to more than four million.

Iran registered 39,357 new cases in the 24 hours to Wednesday, taking the total since the pandemic started to 4,019,084, the health ministry said.

It recorded 409 deaths over the same period taking the total in Iran to 92,194.

The official figures are widely believed to underestimate the real toll but even they make Iran the Middle East country worst hit by the pandemic.

Choked by US sanctions that have made it difficult to transfer money abroad, Iran says it is struggling to import vaccines for its 83 million population.

More than 11 million people have been given a first vaccine dose, but only 2.8 million have received the necessary two jabs, the ministry said.

Iran's supreme leader Ayatollah Ali Khamenei on Monday ordered that "necessary measures" be taken to contain what the government warns is a "fifth wave" of the country's outbreak.

President Ebrahim Raisi chaired a meeting of Iran's Covid task force for the first time Wednesday just a day after his inauguration, his office said.

Iran has avoided imposing a full lockdown on the population, and instead resorted to piecemeal measures such as temporary travel bans and business closures.