Updated

U.S. officials assert Usama bin Laden is still in Afghanistan and the Pentagon has sent in more U.S. troops to hunt the suspected terrorist mastermind.

The Bush administration said that chances of finding bin Laden are improving as the Taliban militia and Al Qaeda terrorist network begin to crumble under increased military pressure.

Pentagon spokeswoman Victoria Clarke said Monday that more American troops were sent Friday into the country's south, where special operations forces have been gathering intelligence and setting up roadblocks to try to catch bin Laden and fleeing Taliban troops. There are a few hundred Americans now on the ground throughout the country, she said.

As U.S. bombing continued Sunday in the Kandahar area in southern Afghanistan and the Kunduz area in the north, the Pentagon said 75 strike aircraft had participated in Saturday's attacks in six target areas near Kabul. It said tunnels and caves used by Taliban and Al Qaeda leaders were among Saturday's targets.

In separate television interviews Sunday, Bush administration officials said bin Laden is on the run, with little chance of gaining safe haven in neighboring countries if he were to escape Afghanistan.

"We're beginning to narrow his possibilities for hiding," Condoleezza Rice, President Bush's national security adviser, said Sunday.

"It's getting harder for him to hide as more and more territory is removed from Taliban control," Secretary of State Colin Powell said on ABC's This Week. "I don't think there's any country in the region that would be anxious to give him guest privileges if he showed up."

Powell said the CIA has been doing "some rather splendid work with respect to our activities in Afghanistan, working alongside our military forces that are inside in Afghanistan."

The Washington Post reported Sunday the CIA has paramilitary forces in Afghanistan; Powell would not confirm that.

"I think we've got a very fine linkup between our intelligence assets, our military assets, all within the framework of a good political and military strategy," Powell said. "And it's now starting to show rather significant results."

Deputy Defense Secretary Paul Wolfowitz said bin Laden was "in very great danger" of being killed or captured.

"This is a man on the run who's doing his best to hide," Wolfowitz told CBS' Face the Nation.

All three administration officials said the United States has no reason to believe bin Laden has fled Afghanistan.

The Taliban's envoy to Pakistan said Saturday that bin Laden had left Afghanistan, but that has not been substantiated. Later, the diplomat said he meant only that bin Laden was outside areas under Taliban control.

If bin Laden were to flee Afghanistan, the United States would keep up the hunt, Wolfowitz said.

"We are going to continue pursuing him," he said. "Let's also remember, we're going to continue pursuing the entire Al Qaeda network, which is in 60 countries, not just Afghanistan and, worst of all, here in the United States. ... This is a campaign against all the global terrorist networks and the states that support terrorism."

Powell said no country on the periphery of Afghanistan, including China, would give bin Laden a haven.

"I don't think this fellow is going to be welcome anywhere," Powell said. "He is an outcast. He is a murderer, he's a terrorist. ... He is on the run, just as the president said he would be. And we will get him."

Rice also left open the possibility that Iraq could become a target in Bush's war on terrorism.

"We do not need the events of Sept. 11 to tell us that [Saddam Hussein] is a very dangerous man who is a threat to his own people, a threat to the region and a threat to us because he is determined to acquire weapons of mass destruction," she said.

Rice cautioned against assuming that the military successes in Afghanistan over the past week meant the United States had met its main objective.

"This may take a while," she said on NBC's Meet the Press.

The Associated Press contributed to this report.