In an address to the Association for Unmanned Vehicle Systems International, Lynch, a former senior army commander in Iraq, said UGVs would comprise a critical element in the U.S. mission in Afghanistan and Iraq.

"We're losing so many soldiers in convoys it's an embarrassment," Lynch said on Aug. 11. "Why does every vehicle have to be occupied by a human being?" .

The general, who also commands the largest U.S. military base, located in Fort Hood, Texas, said the military has sought ways to decrease the heavy casualty toll from Al Qaida and Taliban attacks on convoys.

Officials said the prototypes under consideration have ranged from advanced reconnaissance unmanned aerial vehicles to unmanned ground vehicles meant to reduce the number of soldiers in military convoys. They said the U.S. Army and Marine Corps were discussing the testing of such platforms with several defense companies.

The U.S. military has been examining unmanned platforms by a range of companies, including those from Israel. Several Israeli firms, including the state-owned Israel Aerospace Industries, exhibited at AUVSI in Washington D.C.

"Bring your systems to Fort Hood and allow the soldiers who just got back from combat to use them," Lynch said. "They'll tell you 'This is going to work. I know that ain't going to work.'"

Officials said the U.S. military would come under increasing ground threat, particularly by improvised explosive devices, in both Afghanistan and Iraq. They cited the new restrictions by the Baghdad government in wake of the June 30 redeployment, which limit U.S. military operations to logistics and training.

"The bad guys in Iraq and Afghanistan, they've got their favorite places where they want to place their IEDs," Lynch said.

Lynch said the military wanted to procure effective UGVs that could overcome the limitations of UAVs. He cited the inability of UAVs to see through fog or operate in poor weather.

"The bad guys know that if the weather turns bad we can't see them from the air," Lynch said. "Let's get those kids out of the vehicles."

In 2008, the Defense Department held a competition for a UGV with military and security applications. At one point, the competition, in which there was no clear winner, included Israel's Elbit Systems.

"I am so tired of going to demonstrations of technology," Lynch said.

"The technology is there. We've got to get past the demonstrations and into the field. If you're not fielding, you're failing."