Moving the presidential vote up to spring from August could undercut opponents, who still have to plan their campaigns.
Christians meet underground in a country where official churches do not exist.
The move came shortly after a Taliban group in the nearby Bajur region declared a unilateral cease-fire.
Obama's order to send 17,000 more troops comes before US has set a clear strategy.
Some 3,000 US troops recently deployed to insurgent-heavy provinces near Kabul.
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 US, Pakistan coordinate troops to prevent militants from fleeing to either side.