The missile strike targeted a vehicle near Mir Ali, a major town in the region that borders Afghanistan.
"According to initial reports, the attack destroyed the car and killed three people," an intelligence official said on condition of anonymity.
The official said it was not immediately clear whether any more people were travelling in the vehicle.
The Friday morning attack was the second in North Waziristan in as many days.
Five people were killed and at least two more injured when two missiles believed to be fired from a US drone struck the house of a Taliban sympathiser in the Machikhel area on Thursday night.
The identities of those killed in the two strikes were not known, the official said.
North Waziristan is one of seven districts in Pakistan's tribal region, a suspected enclave of Taliban militants launching deadly assaults on Western troops operating in Afghanistan.
The US has intensified its drone strikes in the rugged territory in recent weeks, apparently as part of its new strategy to tackle the Afghan insurgency.
Pakistan publicly opposes the aerial raids, saying they violate its sovereignty and stoke up anti-American sentiments. But analysts believe that Pakistani intelligence agencies covertly help the US forces in locating and confirming the targets.
Miranshah: A US pilotless aircraft fired a missile into Pakistan's North Waziristan tribal district on Friday, killing three suspected Taliban insurgents, an intelligence official said.
First Published: Friday, January 01, 2010, 14:22