WASHINGTON, Nov 19: A top US commander in the war on terror has said that said that Pakistan's unprecedented decision to deploy forces in the tribal region has cut off Osama bin Laden from his terrorist operatives.

Also on Thursday afternoon, the top US Marine commander in Iraq told a briefing at the Pentagon that the US victory in Fallujah has "broken the back" of the Iraqi insurgency.

Lt-Gen Lance Smith, the deputy chief of US Central Command told reporters at Washington's Foreign Press Center that the deployment of Pakistani troops along the Afghan border had dealt a blow to Osama and top aide Ayman al-Zawahri.

The Pakistanis have attacked and killed hundreds of terrorists loyal to Al Qaeda, putting pressure on their leaders, said the US commander. "They are living in the remotest areas of the world without any communications -- other than courier -- with the outside world or their people and unable to orchestrate or provide command and control over a terrorist network," Gen Smith said.

"They are basically on the run and unable to really conduct operations except in very long term, provide vision and guidance as Osama does when he provides one of those tapes," said Gen Smith, referring to Osama's recent video that railed against President Bush before the Nov 2 election.

The United States thinks that during the war, Osama moved from Kandahar to the Tora Bora mountain range, from where he crossed into Pakistan's tribal zone avoiding an intensive manhunt.

Meanwhile, Lt-Gen John Sattler, who commands the 1st Marine Expeditionary Force in Iraq, told Pentagon reporters that 11 days after invading Fallujah, the one-time insurgent stronghold is secure, but not yet safe. His ground troops were carrying out a "search-and-clear phase," he said.