Washington - President Barack Obama was expected to start his second week in office with major announcements to force rapid improvements in fuel efficiency for cars sold in the United States, The New York Times reported on its website.

Obama was expected to overturn policies of his predecessor, president George W Bush, to allow 14 states led by California to tighten standards for fuel efficiency and emissions from cars.

The US Environmental Protection Agency will be ordered to reconsider the application by individual states, which sought federal permission to set their own, tougher standards for new cars sold in their states, the Times reported, citing two officials in Obama's administration.

California is the most populous US state and would rank among the world's 10 largest economies if it were a separate country. Its market is so large that most cars sold in the United States are designed to meet California requirements, allowing the state in the past to push nationwide improvements in areas such as safety and emissions.

Obama is also expected to order the US Transportation Department to hike its own fuel-efficiency standards for new cars, the Washington Post reported online, citing sources briefed on Monday's announcement. (dpa)