Some 3,000 US troops recently deployed to insurgent-heavy provinces near Kabul.
Militants signed a cease-fire with provincial authorities Monday after they agreed to impose sharia.
Fearful that US failure there could unleash the Taliban and other Islamist insurgencies, Russia may help NATO open a supply line through former Soviet territory.
The militants released a Chinese engineer held hostage for nearly six months ahead of the cease-fire announcement.
The US, Pakistan coordinate troops to prevent militants from fleeing to either side.
Insurgents attacked three government offices in a heavily fortified area Wednesday, a day before US envoy Holbrooke's visit.
The special representative launched his three-day visit in Pakistan Tuesday with an aim to 'listen and learn,' but also to urge the US ally to eliminate its militant havens.