The Islamist extremist group Pakistani Taliban has pledged support for its fellow militant organisation Isis to establish a global caliphate.

Marking the Muslim festival of Eid-al-Adha, the group, which has been engaged in an armed insurgency against the Pakistani government, hailed the achievements of its "brothers" in Iraq and Syria.

Taliban spokesperson Shahidullah Shahid said in a statement: "We are proud of your conquests against the enemies. We are with you in good and bad times. In these troubled days, we call on you to be patient and stay united as your enemies are now united against you. Forget rivalries."

The statement was issued on behalf of Maulana Fazlullah, the chief of the insurgent group which is officially known as Tehreek-e-Taliban.

"All Muslims in the world have great expectations of you… we are with you, we will provide you with Mujahideen [fighters] and with every possible support," the statement added.

There is no formal alliance between the two groups, but the latest announcement suggests there are no serious differences between the two groups.

Recently, supporters of Islamic State were seen distributing pamphlets in the Pakistani city of Peshawar.