The group's spokesman Ahsanullah Ahsan said the boys were kidnapped because they belong to a tribe opposed to the militants. He said the Taliban will decide the boys' fate and set conditions for a possible release.
Pakistani officials have said the boys, who are between 12 and 15 years old, were seized on Thursday in Afghanistan's Kunar province after crossing over from their villages in the Bajur border region. They were allegedly lured by a man who invited them to play in a river.
Ahsan did not say where or how the boys were seized, only that the Taliban are holding them. He also claimed they are over 20 years of age, significantly higher than the age given by Pakistani officials.
"They belong to a tribe that is always up against the militants," Ahsan told The Associated Press over the phone from an undisclosed location.
Militants often target people from tribes who oppose -- or do not support -- them.
Also, large groups of militants from Afghanistan have been attacking security checkpoints in Pakistan in recent months in deadly cross-border raids. The Pakistani army has said the attackers are militants who fled the military's offensives in Pakistan and are using Afghan soil as a safe haven.
The Taliban announcement on holding the boys appears to strengthen that claim. It is also an indication of the complexity of fighting militants along the volatile and porous border.
On Friday, the top Pakistani official in Bajur, Islam Zeb, said the militants initially seized around 40 boys but released those under the age of 12 and allowed them to travel back home.