Republicans on Capitol Hill Wednesday said the Obama administration's economic stimulus plan has been mishandled and overly optimistic about U.S. job creation.

Rep. Darrell Issa, R-Calif., was among the GOP members of Congress who said at a House committee hearing that the $787 billion spending plan had failed to create jobs and hold unemployment at 8 percent.

"I am convinced that it won't work," said Issa. "Unfortunately, recent economic data has validated my opposition."

The jobless rate hit 9.5 percent in June, the United States lost 3.4 million jobs in the past six months as the recession showed greater tenacity than expected.

CNN said White House officials defended the stimulus, telling the House Oversight and Government Reform Committee that more time was needed for the package to show results.

"We are slowing the economic free fall (and) the recovery act is an important part of that effort," said Rob Nabors, deputy director of the White House Office of Management and Budget. "It is a work in progress, but it is steady progress."