A government spokesman says Pakistan has summoned Afghanistan's ambassador to protest President Hamid Karzai's threat to send Afghan troops to fight notorious Taliban leaders inside Pakistan.

Foreign Ministry spokesman Mohammed Sadiq said a "strong protest" was lodged Monday with Afghan Ambassador Anwar Anwarzai at the Foreign Ministry in Islamabad.

Karzai said Sunday that Afghanistan has a right to send troops into Pakistan because Taliban militants cross over from Pakistan to attack Afghan and foreign forces.

Analysts say Afghanistan is unlikely to do so, but Karzai's comments marks a new low in bilateral relations, often strained over allegations that Taliban and al-Qaida find sanctuary in Pakistan's border regions.