Libya's embattled leader Moammar Gadhafi has not been seen in public since a NATO air strike levelled much of his family compound to rubble, but America's intelligence chief says he's still alive.

CIA Director Leon Panetta made the remark during an interview with U.S. TV network NBC on Tuesday.

When asked if he has any evidence Gadhafi survived the strike that Libyan officials say killed one of his sons and three grandchildren at his official residence in Tripoli, Panetta was blunt.

"The best intelligence we have is that he's still alive," he said, prompting anchor Brian Williams to inquire whether he has actually seen positive proof.

But Panetta did not elaborate.

"Best intelligence we have on Gadhafi is that he's still alive," he repeated.

Libyan officials have taken journalists and photographers to tour the Bab al-Aziziya compound in the days since the April 25 air strike, telling them that Gadhafi was there when two powerful guided bombs struck, but survived.

They have not provided any further details besides assurances Gadhafi is still working.

The latest came in a news conference late Tuesday, when Libya's deputy foreign minister Khaled Kaim told reporters that Gadhafi was indeed alive and had met with tribal leaders earlier in the day.

He refused to praise or condemn the U.S. mission that ended in the death of Osama bin Laden, instead offering his assurances that Libya has long fought against the al Qaeda terror network.

Gadhafi has been struggling to retain his four-decade grip on power since an armed uprising began in February. While rebels control much of eastern Libya, they're locked in a stalemate with Gadhafi's forces in the west.

NATO is engaged in a UN-mandated campaign to enforce a no-fly zone and protect civilians in Libya.

The commander of NATO's operation, Canadian Lt. Gen. Charles Bouchard, has said the air strike on the presidential complex was aimed at an army command centre there and not Gadhafi himself.