In an interview on CBS' "Face the Nation," Biden described the security conditions in Afghanistan, Pakistan and Iraq -- a trio of countries he recently visited -- and President Barack Obama's decision to close the U.S. detention center in Guantanamo Bay, Cuba.

He said Afghanistan has deteriorated due to a failure to provide sufficient economic, political and military resources, as well as a lack of coherent policy among allies involved there. The Taliban are in "effective control" of significant parts of the country, he added.

"The bottom line here is we've inherited a real mess," he said. "We're about to go in and try to essentially reclaim territory that's been effectively lost."

Biden said more troops are necessary in Afghanistan, where an estimated 25,000 additional U.S. forces are expected to deploy over the next 12 to 18 months, according to defense officials. Some 34,000 U.S. servicemembers currently are there.

"It's going to require ... some additional military forces. There are going to be additional efforts to train their police and to train their Afghan army," he said. "And all of that means we're going to be engaging the enemy more."

Describing other factors in Afghanistan, the vice president said corruption is rife among the ranks of Afghan National Police, and that the country is the source of 95 percent of the world's opium and heroin.

Asked if intensified engagement would lead to more American casualties, Biden said, "I hate to say it, but yes, I think there will be an up-tick."

"As the commander in Afghanistan said, 'We will get this done, but we're going to be engaging the enemy much more,'" Biden said, quoting Army Gen. David D. McKiernan, commander of NATO's International Security Assistance Force and U.S. forces in Afghanistan.

Biden met with McKiernan earlier this month during a Middle East fact-finding mission that brought the then-vice president-elect to Afghanistan, Pakistan and Iraq.

The vice president said the United States is making progress in Pakistan, where the national army has increased its level of cooperation in policing a contentious region near the Afghan border known as the federally administered tribal areas, which he characterized as an ungovernable swath of land that is home to al-Qaida and other enemy combatants.

"We're in the process of working with the Pakistanis to help train up their counterinsurgency capability, their military, and we're getting new agreements with them about how to deal with cross-border movements of these folks," he said. "So we're making progress."

He underscored that the president has pledged he would not hesitate to use action against high-level al-Qaida personnel in the area.

Using a football metaphor to describe the situation in Iraq, Biden said the United States is on the 20-yard line, which in football terms is 80 percent of the way to the goal.

"But now comes the really hard part. The surge did work. Our military has done everything we've asked of them, but there needs to be a political reconciliation in Iraq," he said, pointing to the three elections slated for 2009 as key indicators.

He also emphasized the need for laws determining how oil revenues and political power will be distributed. Biden hailed the status-of-forces agreement that took effect Jan. 1 and will guide the security relationship between Washington and Baghdad as a "strong sign" of Iraqi political movement.

"There's progress being made on it," he said of reconciliation among Iraq's ethnic groups, "but we need a much stronger push, and there has to be an additional show of responsibility on the part of the Iraqi leaders that they're able to govern."

Biden also discussed Obama's order to close the Guantanamo Bay detention center in Cuba within a year. He said shuttering the facility presents difficult decisions, including where to relocate detainees, but that closure will be achieved within the 12-month timeline.

The vice president said detainees will not be released within the United States because, aside from one detainee, they are not American nationals, and therefore have no legal status in America.

"They're either going to be moved and tried in American courts or they're going to be sent back to their countries of origin," Biden said. "If they are not a U.S. citizen or if they are not here legally, then even if they were released by a federal judge, they would not be able to stay here in the United States."

Biden acknowledged that some countries have indicated they do not want to repatriate detainees. White House Counsel Greg Craig is reviewing detainees on a case-by-case basis, he said, adding that other countries have agreed to allow prison facilities for holding enemy combatants captured on the battlefield.

"What I anticipate happening is that those people who are in a situation where it is either the evidence is in question or it's going to be hard to make a case, we will most likely be rendering them back to their countries of origin or another country," he said.

The vice president said the new Obama administration is still determining what it has inherited in the detention facility.

"The one thing we do know is that the maintenance of Guantanamo, its symbol and the consequences of this symbolism around the world, it has grown terrorist organizations, not diminished terrorist organizations," he said.