WASHINGTON - White House counterterrorism chief John Brennan said al Qaeda is "on a steady slide" after the death of al Qaeda's latest second-in-command in Pakistan.

Brennan told The Associated Press on Wednesday that it's a "huge blow" in the first official White House comment since Atiyah Abd al-Rahman's reported killing by CIA drone strike in Pakistan's tribal areas last week.

"Al Qaeda is sort of on the ropes and taking a lot of shots to the body and the head," Brennan said.

"This is a time not to step back and let them recover," a message he says he's sending to his counterparts in Pakistan.

Islamabad's objections to drone strikes have become more strident since the U.S. raid that killed Osama bin Laden in May. Despite that friction, Brennan said the relationship with Pakistan is improving.

In a wide-ranging interview, Brennan credited aggressive U.S. action against militants from Pakistan to Yemen as the main reason U.S. intelligence has detected no active terror plots before the tenth anniversary of the 9/11 attacks.

He described the counterterror relationship with Pakistan, Yemen and Iraq as models of how the U.S. will fight al Qaeda in the future -- where the lion's share of the hunting and fighting is done by the host nation. He said the U.S. was looking ahead to crafting a similar model in Afghanistan as U.S. troops draw down there, where as in Iraq and Yemen, small numbers of U.S. intelligence and special operations forces will work with their counterparts, providing training, equipment and sharing intelligence to track terror targets, and keep them under pressure.

"If they're worrying about their security ... they're going to have less time to plot and plan," Brennan said of the militants. "They're going to be constantly looking over their shoulder or up in the air or wherever, and it really has disrupted their operational cadence and ability to carry out attacks."

He pointed to the killing of Al-Rahman as an example of how U.S. pressure is degrading the network.

"There's no longer a management grooming program there. They don't stay in place long enough," Brennan said.

Al-Rahman had barely assumed a leadership position since bin Laden's death pushed his deputy, Ayman al-Zawahri, into the top spot. Brennan described Al-Rahman as a "workaholic" and an "operational mastermind" who kept al Qaeda's nodes from Yemen to Europe connected.

"Taking him out of commission is huge," Brennan said. "There's not another bin Laden out there. I don't know if there's another Atiyah Abd al-Rahman out there."

Brennan said the key to keeping another Al-Rahman from rising is to keep constant pressure on all locations where al Qaeda operates, working through host countries to target a network of operatives that "are flowing sometimes back and forth" from Pakistan, Afghanistan, Iraq, Yemen and Somalia as well as parts of the African Sahel.

He admitted that efforts to keep pressure on across that network hit a "speed bump" when the "Arab Spring" swept U.S.-friendly governments, and counterterrorism personnel, out of office.

But he said in Egypt, U.S. contacts have been able to recover quickly following longtime leader Hosni Mubarak's ouster earlier this year. The counterterrorism relationship with Tunisia, where the Arab Spring movement began, also remains strong, he said.

Brennan said the uprising in Yemen, however, had kept Yemeni forces engaged in a fight for political survival, and had slowed down the fight against arguably the most dangerous bin Laden affiliate, Al Qaeda in the Arabian Peninsula.

AQAP, as the affiliate is known, has worked with the rebel tribes to grab large swaths of territory in the south.

The unrest has forced the U.S. to draw down the hundred-plus military and intelligence personnel it had working with Yemeni counterterrorism forces. Those Yemeni forces, led by ailing Yemeni President Ali Abdullah Saleh's sons, have been reluctant to leave the capital unguarded, even when a brigade of conventional Yemeni troops became trapped by al Qaeda in the Abyan region.

"This political tumult is ... leading them to be focused on their positioning for internal political purposes as opposed to doing all they can against AQAP," he said.

U.S. forces had to air drop foot and water aid to the embattled unit, which was threatening to surrender. Brennan says the U.S. has since persuaded the Yemenis to send enough forces their way to free them, and that he's urged the country's vice-president to send more troops into the fight.

Yemeni president Saleh is still recovering in Saudi Arabia with some 70 per cent of his body burned and a lung pierced from an assassination attempt in June as he was praying in his palace compound.

While Brennan says Saudi Arabia would allow Saleh to return from his temporary medical exile, he repeated the White House's earlier calls for Saleh to stay away and let new elections take place.

"I've told him that I do not believe it's in his interests, Yemen's interests or our interests ... to go back to Yemen," Brennan said.

He called Yemen a "tinder box" that could spark into a civil war that al Qaeda would take advantage of.