BEIJING — China has stepped up pressure on automakers to accelerate development of electric cars by raising its first-year target for production quotas but delayed their rollout from next year until 2019.

The announcement is the latest step in aggressive plans to make China a leader in electric car technology. Communist leaders see them as a way to clean up China's smog-choked cities and create a profitable industry.

Electrics will have to make up at least 10 percent of each automaker's output, up from 8 percent in an earlier proposal, and those that fail to meet their targets can buy credits from competitors that do. The launch was postponed from next year until 2019.

Beijing's support for electric vehicle sales has made China the biggest market for the technology.