The US government will make 400 million non-surgical N95 masks from its strategic national stockpile available for free to the public starting next week, a White House official said, marking the Biden administration's latest effort to help curb the Covid-19 pandemic.

The face masks will be shipped to pharmacies and community health centres this week, the official said, and available for pickup late next week.

The move comes after US President Joe Biden and his team faced criticism for not doing enough to foster masking or bolster testing as the Omicron variant raged across the country.