The fate of children would be decided by TTP`s central council, the group`s spokesman Ehsanulah Ehsan said claiming that they had kidnapped the youth as their parents were helping the Pakistan army in their drive against it.
Their kidnapping has raised fears that the children might be used as suicide bombers.
The terror group said they were "anxiously waiting" for the Pakistani children from Bajaur tribal region to come to the mountains for celebration of Eid.
Children from Bajaur tribal region, who had gone for picnic to celebrate `Eid` had mistakenly crossed into bordering Kunar province on Thursday.
The group is holding 25 children aged 18 to 20 as hostages, Ehsan said.
However, Pakistani officials said the boys are aged between 10 to 15.
Officials had earlier said that over 30 children were held hostage by militants.
Sources said that several children escaped and reached back to their homes.
The Taliban spokesman said that parents of the hostage youth are pro-government tribesmen and have formed committees against the Taliban, who had fled Bajaur tribal region after the major military offensive in 2008-9.
Ehsanullah said the Taliban`s central `Shura` or council will decide fate of the youth and the council has started identification process of the hostages.
Officials said that many children from the major Mohmand tribe had gone for picnic in the mountainous areas and mistakenly crossed into Afghanistan as there is no determined border in the area.