Zabihullah Mujahed, a spokesman for the Taliban, told the BBC by phone the conservative Islamic force, which ruled Afghanistan before the U.S.-led invasion in 2001, would defeat NATO-led forces still deployed in the country.
"We're sure they'll be defeated," he said in an interview published Friday. "The foreign forces ... are so scared they're confined to their bases."
International combat obligations draw to a close this year as Afghan forces assume a greater responsibility over national security. Washington said its obligations may end sooner than later unless the Afghan government signs a bilateral security agreement.
Afghan President Hamid Karzai said he'd defer the matter to the next president who takes office after April elections.
Mujahed said the Taliban were gaining a foothold in parts of Afghanistan once controlled by international forces.
He said, however, his organization had "no relationships" with any of the dozens of candidates cleared to take part in presidential elections. He said the April contest was a "fake process."