The U.S. government's cash for clunkers autos sales incentive program may be wound down as soon as early September, the Wall Street Journal said, citing a person familiar with the matter.

The U.S. government is expecting a surge in last-minute clunker deals when a closing date is announced and wants to avoid a situation where dealers agree to sales after the program's funds have been exhausted, the person told the paper.

Under the program, the government gives consumers a rebate of up to $4,500 for trading in older, inefficient vehicles for new, fuel-sipping ones. Washington scrambled early this month to add $2 billion when the popular program's initial $1 billion funding was quickly spent.

The U.S. Department of Transportation did not immediately respond to a Reuters email seeking comment.

(Reporting by Ajay Kamalakaran in Bangalore; Editing by Hans Peters)