Two Japanese automakers on Wednesday unveiled measures to boost their capacity to procure batteries, with Nissan saying it will acquire one of its key suppliers, as the producers look to accelerate the development of electric vehicles.

The announcements come as automakers worldwide expand their efforts to roll out the less-polluting, electrified cars amid stricter environmental regulations.

Nissan said it will acquire lithium-ion battery maker Vehicle Energy Japan for an undisclosed sum to secure a stable supply of batteries and facilitate the development of next-generation batteries.

The automaker said it will buy the 47% stake in Vehicle Energy Japan held by the state-backed fund INCJ, and purchase more shares to be issued by the battery maker.

Vehicle Energy — which is based in Hitachinaka, Ibaraki Prefecture — is currently providing lithium-ion batteries to Nissan vehicles such as its flagship compact car Note.

With the deal, Vehicle Energy will become a consolidated subsidiary of Nissan, and its existing shareholders Maxell, another battery manufacturer, and Hitachi Astemo, an auto parts maker, will continue to hold their stakes, according to Nissan.

Also on Wednesday, Honda said its Chinese unit will set up a joint venture later this month with local automakers Dongfeng Motor and Guangzhou Automobile Group to jointly procure EV batteries.

The Japanese automaker said it will strengthen its partnership with Chinese automobile battery giant Contemporary Amperex Technology, commonly known as CATL, to beef up its battery supply chain.

Honda said last month that together with LG Energy Solution, it will spend $4.4 billion to build an EV battery plant in the United States.

Toyota said in the same month it will invest up to ¥730 billion in the U.S. and Japan to increase its battery production capacity.