The United States can deal with Al-Qaeda's spreading presence in Yemen without US forces on the ground, relying instead on targeted operations, US Defense Secretary Leon Panetta said Sunday.

Panetta, in an interview with ABC television's "This Week," defended the use of drones as "the most precise weapon we have" in the campaign against Al-Qaeda.

"Our whole effort there is aimed at going after those terrorists who threaten to attack our country," he said.

"We've been successful. We've gone after a number of key targets there. We'll continue to do that."

Al-Qaeda in the Arabian peninsula, which US intelligence considers a top threat to the US homeland, has expanded its presence in Yemen amid unrest and political turmoil there.

The Yemen-based Al-Qaeda affiliate has twice tried to bring down US airliners, including the failed underwear bombing of a Detroit-bound jet on December 25, 2009.

Panetta was asked whether Al-Qaeda could be stopped without US boots on the ground.

"The answer is yes, because very frankly, what we're targeting, the operations we're conducting, require the kind of capabilities that don't necessarily involve boots on the ground, but require the kind of capabilities that target those that we're after who are threats to the United States."

The United States has military advisers assisting Yemeni forces and has carried out regular drone strikes against Al-Qaeda suspects there, mainly in the south and southeast.

Yemen's army launched a major offensive on May 12 to capture Al-Qaeda-controlled areas in the southern province of Abyan.

A suicide bomber blew himself up last week in the middle of an army parade rehearsal in the capital Sanaa, killing 96 soldiers and wounding at least 300 others.

Al-Qaeda said it was behind the attack, the deadliest against Yemeni troops since newly-elected President Abdrabuh Mansur Hadi vowed to destroy the militant network at his swearing in ceremony last February.