U.S. and NATO forces in Afghanistan are re-balancing strategies of counterinsurgency and counterterrorism to confront the realities on the ground, a top U. S. military official said Wednesday.

"The COIN (counterinsurgency) strategy is balanced by a counterterrorism strategy," said Marine Corps Gen. James E. Cartwright, vice chairman of the U.S. Joint Chiefs of Staff.

"When we started, we probably were more aligned with counterinsurgency. The emphasis is shifting," he told attendees at the Government Executive 2010 Leadership Briefings held at the National Press Club.

The existence of enemy safe havens necessitates the shift, the general said. Taliban and foreign terrorists can launch attacks in Afghanistan, then escape over the border into the Tribal Areas of Pakistan. There, the enemy is able to rest, refit and plan further attacks with their lines of communication intact.

"We need to reduce those lines of communication and reduce that flow to the best of our abilities," Cartwright said. "So the balance of the force that was really weighted more toward counterinsurgency is starting to shift to have an element of counterterrorism larger than we thought we were going to need when we started."

The Obama administration is expected to deliver a review of its Afghan strategy to the Congress later this month. The president ordered the deployment of 30,000 additional troops to Afghanistan late last year, but the troops made few progress in changing the outlook of the war.

The Defense Department late last month released a report describing security developments in Afghanistan from April to September. It found violence in Afghanistan not only didn't subside, but was at all-time high since the nine-year-old war started, and progress made by foreign troops there were limited.