The charity, which has six expatriate workers in Pakistan, said it had received no explanation for the order, but it has reportedly come under suspicion over the US raid that killed Osama bin Laden in May 2011.
Media reports have linked Save the Children to Shakeel Afridi, a Pakistani doctor who was jailed for 33 years for treason after helping the CIA hunt down the Al Qaeda chief using a fake vaccination programme.
“Earlier this week we got a call from special branch instructing us to send back all expatriate staff,” Save the Children spokesman Ghulam Qadir told AFP.
“There were no reasons given. We are working with the government to comply with the instructions.
“We will continue to operate in Pakistan and Save the Children is currently serving more than seven million children with 2,000 dedicated national staff.
“Our commitment is that we will continue to carry out our programme activities to meet the needs and rights of the children.”
Save the Children denied allegations that it was used as cover during the hunt for bin Laden.
“On Shakeel Afridi, our stand is very clear that there is absolutely no truth in it. There is no concrete proof to these allegations”, Qadir said.
He said initially the government had asked the foreign staff to leave within two weeks but the time was extended after a request.
No government official was immediately available to comment.