PHOENIX —  Homeland Security officials have told federal lawmakers that the "virtual fence" along the U.S.-Mexico border in Arizona doesn't meet contract requirements for detecting border intrusions and some of its technology will have to replaced by this summer.

Agency officials, testifying Wednesday before the oversight panel of the House Homeland Security Committee in Washington, D.C., said plans to expand the system to the Yuma, Ariz., and El Paso, Texas, areas will be pushed back three years to 2011 because of technological deficiencies.

The 28-mile virtual fence will use radars and surveillance cameras to try to catch people entering the country illegally.

The Sasabe network, called Project 28, was intended as a cornerstone of the government's multibillion-dollar border strategy.

As hundreds of miles of physical barriers and thousands of Border Patrol agents are being added, technology anchored by the virtual fence was to fill the gaps.

"Project 28 was supposed to be an example of how we could use technology to secure the border. The lesson is we can't secure 28 miles of our border for $20 million," said committee member Rep. Bill Pascrell Jr., D-N.J. "After so many years of promises and tests and millions of dollars spent, we are no closer to a technological solution to securing the border. This is unacceptable. It's what's holding up comprehensive immigration reform."

Critics say contractor Boeing Corp. never consulted border agents before engineering the system.

A Boeing executive testified that the company spent more than double the value of the $20 million contract to set things right and is now refining the network.

The Department of Homeland Security awarded Boeing a $64 million contract to improve the network in December, two months before the government accepted the Sasabe work.

Amy Kudwa, a Homeland Security spokeswoman, said that the virtual fence is not in full operation and that the agency continues to test the system.