Afghanistan is one of the world's poorest countries, wrecked by decades of conflict which led to the rise of the Islamist fundamentalist movement, the Taliban.
Despite the fall of the Taliban after the US-led invasion of Afghanistan in 2001, the security situation remains tense as extremists continue to stage regular attacks.
The Pakistani army has recanted its statement on a "Dawn Leaks" civilian-military rift that purportedly undermined the premier's authority. Pro-democracy groups say it's a rare victory for Sharif over the army generals.
Iran has warned it would target militant hideouts inside Pakistan if Islamabad doesn't act against Sunni jihadists. Pakistan's other two neighbors - Afghanistan and India - also accuse Islamabad of backing terrorists.