Earlier Wednesday, surgeons removed a bullet from Yousafzai, who was shot by the Taliban for speaking out against the group and promoting education for girls.
The shooting has drawn condemnation from the United Nations, rights groups and world leaders, as well as many Pakistanis. White House spokesman Jay Carney said Wednesday that the United States had offered any assistance necessary.
“The president found the news reprehensible and disgusting and tragic,” Carney said.
Yousafzai began standing up to the Pakistani Taliban when she was just 11, when the government had effectively ceded control of the Swat Valley, where she lives, to the militants.
Her father, Ziauddin Yousafzai, who runs a school for girls, said his daughter had defied threats for years, believing the good work she was doing for her community was her best protection.
A Reuters correspondent watched as she was moved from an army hospital in the regional capital, Peshawar, to the Armed Forces Institute of Cardiology in Rawalpindi.
“Pray for her,” her distraught uncle, Faiz Mohammad, said before the ambulance left the hospital.
A husband-and-wife team of British doctors who were attending a seminar in Pakistan at the time of the attack joined local surgeons Thursday in treating Yousafzai.
She was shot with two other girls as she left school in Swat, northwest of Islamabad, the nation’s capital. One of the girls is out of danger; the other remains in critical condition.
A Taliban spokesman said that Yousafzai was targeted for trying to spread Western culture and that the group would try to kill her again if she survived.
Authorities have identified her attackers, said regional governor Masood Kausar, and the local government has posted a $100,000 reward for their capture. “The security agencies are closely working with each other, and they have a lot of information about the perpetrators,” Kausar said.
Small impromptu rallies in support of Yousafzai were held in many cities Thursday and in her home town of Mingora. Schools also closed across Swat to protest the shooting.