TOKYO (Reuters) – SoftBank Group Corp CEO Masayoshi Son said he has secured a monthly supply of 300 million face masks for Japan from May after reaching a deal with Chinese electric vehicle maker BYD Co Ltd, which has also started producing masks.

SoftBank will donate two different kinds of mask, initially for medical staff, in cooperation with the Japanese government’s “mask team”, set up to tackle shortages due to the coronavirus outbreak, Son said on Twitter.

Addressing the supply crunch is a priority for the Japanese government, which will begin delivering two washable masks to households next week — a move that has been widely criticised on social media as inadequate.

The government is also targeting domestic production of 700 million disposable masks.

Son, who has a long history of partnering with and investing in Chinese firms, said BYD is setting up a new line to produce the masks.

BYD’s production capacity has reached 15 million masks a day, a company spokeswoman said, confirming the firm will supply masks to SoftBank.

SoftBank’s supply will consist of 100 million N95 masks, which can filter very small particles, and 200 million regular surgical masks.

The coronavirus pandemic has spurred Son’s return to Twitter, where he has complained that Japan’s response is being spearheaded by politicians rather than scientists and polled users on their view of the government’s response — adding to pressure to increase social distancing measures.