Terrorist safe havens in Pakistan pose serious problem: NATO

General John "Mick" Nicholson who succeeds General John F. Campbell as the NATO forces commander in Afghanistan, said terrorist safe havens inside Pakistan were a serious challenge.

"I view it [terrorist safe havens inside Pakistan] as a serious problem. This has been one of the principal challenges. It's a sanctuary that our enemies, in particular the Haqqani Network, have enjoyed inside Pakistan," Tolo news quoted Nicholson as saying on Thursday.

"I note that the Pakistanis have also suffered significant casualties in the tens of thousands in terms of their security forces and their civilians," he said.

"Some of this has pushed some fighters into Afghanistan, which has contributed to some of the issues there. So, it's a mixed story, and it's one that requires continuous engagement by the Pakistan military. And then, increasingly, we want to encourage the Afghans and the Pakistan military forces to work more closely together against their common enemies," Nicholson said.

Haqqani Network is blamed for several deadly attacks against Afghan and foreign forces in Afghanistan.