President Barack Obama is ordering a new crackdown on federal contractors who don't pay their taxes.

He was signing an executive order Wednesday telling federal agency chiefs to take steps to bar those companies from receiving new government contracts. Obama was also directing the IRS to review contractor filings to ensure the companies are not lying about the taxes they've paid.

"It is simply wrong for companies to take taxpayer dollars and not be taxpayers themselves," Obama said in his prepared remarks. "We need to insist on the same sense of responsibility in Washington that so many of you strive to uphold in your own lives, in your own families and in your own businesses."

A White House fact sheet said the move is part of the president's effort to restructure government contracting to root out waste and abuse.

That effort has included measures to end no-bid contracts and to crack down on what the administration deems improper payments. Administration officials estimate the measures saved as much as $100 billion last year.

Obama said studies by the Government Accountability Office have estimated that the U.S. is owed more than $5 billion in unpaid taxes by thousands of companies that are being awarded government contracts.

The White House said Obama is also urging Congress to give the administration additional tools to ensure tax dollars don't benefit companies that are in arrears to Uncle Sam. Among the powers being sought: allowing the IRS to share tax data with agency contracting chiefs to help officials catch tax scofflaws.