Updated

Pakistan's military has been so effective in pressuring Al Qaeda (search) leaders hiding in the tribal region of western Pakistan that Usama bin Laden and his top deputies no longer are able to direct terrorist operations, a senior American commander said Thursday.

"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," said Lt. Gen. Lance Smith (search), deputy commander of Central Command.

"They are basically on the run and unable to really conduct operations except, in the very long term, provide vision and guidance as Usama bin Laden does when he provides one of those tapes," he added, alluding to a bin Laden video tape released three weeks ago.

Bin Laden has been on the run since U.S. forces invaded Afghanistan in October 2001.

In a question-and-answer session at the Foreign Press Center, Smith said that for the first time since Pakistan was enlisted as a U.S. ally against Al Qaeda, the Pakistani military forces hunting for Al Qaeda figures will remain in the western tribal region through the winter.

"It is essential that Pakistan military continue their operations," he said, adding that over the past three to six months they have made "very, very positive moves" against Al Qaeda.

South Waziristan, a semiautonomous tribal region along the border with Afghanistan, long has been regarded as one of the most likely hiding places for bin Laden and his deputy, Ayman al-Zawahri, although there has been no solid intelligence to confirm that.

Between 7,000 and 8,000 Pakistani forces have been deployed in a three-pronged offensive in the eastern reaches of the rugged region this month. U.S. military forces remain largely on the Afghanistan side in hopes of capturing or killing any Al Qaeda operatives who cross the border.

"We will continue to search them out. We will find them," Smith said.

The three-star general likened the military effort against bin Laden to the work being done in Iraq to keep terrorist leader Abu Musab al-Zarqawi and other insurgents on the run so "they cannot stay any place for any length of time," thereby reducing their effectiveness.

Smith suggested Central Command may increase the size of the U.S. force in Iraq prior to national elections scheduled for late January.

"As we move closer to elections we will make adjustments to our troop strength to ensure that we will have forces to be able to back up the Iraqi security force in sufficient numbers," he said.

Smith did not say explicitly that more U.S. troops would be sent to Iraq. At one point he said there was no need for "a huge increase" in troops, seemingly suggesting that a smaller increase was possible.

There now are between 135,000 and 140,000 U.S. troops in Iraq, he said.

Addressing an issue that has received little public attention in the United States recently, Smith said the United States is sharing intelligence with Turkey on a Kurdish rebel group that operates in northern Iraq. The group, known as the PKK, is considered a terrorist organization by the United States and Turkey.

"We will continue to work with the interim Iraqi government to expel them from the country," Smith said.

"It's a difficult task," he said. "To dig them out and engage that fight I think will take a considerable amount of forces, and we need to do that at the right time."