The Pakistani schoolgirl shot in the head by the Taliban last week has arrived in the UK for specialist medical treatment.
The spokesperson said in a statement on Monday that 14-year-old Malala Yousafzai, whose shooting has drawn condemnation abroad and at home, will require "prolonged" care to fully recover physically and psychologically.
She is in a serious condition and is being taken to Queen Elizabeth Hospital in Birmingham for treatment.
Malala was flown from Pakistan on board an air ambulance provided by the United Arab Emirates and accompanied by a full medical team.
Malala - who has been campaigning for education for girls - was attacked last Tuesday as she was returning home from school in Mingora in northwestern Swat.
"The panel of doctors recommended that Malala be shifted abroad to a UK centre which has the capability to provide integrated care to children who have sustained severe injury," said the army spokesperson in the statement.
Al Jazeera's Andrew Simmons, reporting from Birmingham, said: "The hospital is a trauma centre. It is one of the biggest in the world provided by the National Health Service, but the treatment will be paid for by the United Arab Emirates.
"This hospital specialises in brain injury."
Its specialist team has 10 years of experience of treating UK military casualties and Medical Director Dr David Rosser said Malala Yousafzai "could be viewed as a battle casualty", which put doctors there "in a good position to treat her".
Security, he added, was taken very seriously "at the best of times".
A source in a hospital in the city of Rawalpindi, where she was initially being treated, told Al Jazeera on Sunday that her condition was "critical" and that she had a slim chance of recovering.
The shooting of Yousafzai has been denounced worldwide and by the Pakistani authorities, who have offered a reward of more than $100,000 for the capture of her attackers.
The attack has angered Pakistan, where Malala won international prominence with a blog that highlighted atrocities under the Taliban who terrorised the Swat Valley from 2007 until a 2009 army offensive.
Activists say the shooting should be a wake-up call to those who advocate appeasement with the Taliban, but analysts suspect there will be no seismic shift in a country that has sponsored radical Islam for decades.
Local police officials told Al Jazeera that the investigation into who was responsible for the attack was ongoing. The perpetrators were witnessed escaping into a nearby slum.
Four people have been arrested in connection to the shooting. They were among about 60 to 70 suspects rounded up in the Swat region this week, but all were subsequently released.