ISLAMABAD - Beijing has been playing a key role to mediate between Iran and Pakistan after Tehran made a formal request to this effect, The Nation reported while quoting unnamed sources on Monday.

The relationship between both countries has been strained since news broke in Pakistan regarding Indian spy Kulbushan Yadhav, who allegedly based part of his operations to destabilize Balochistan and Karachi from Iran.

Prime Minister Nawaz Sharif's National Security Adviser General (r) Naseer Khan Janjua visited Tehran last week to set a clear direction Pak-Iran relationship.

Janjua was invited by the secretary of Iran’s Supreme National Security Council, Ali Shamkhani, after mediation by China. He had very fruitful meetings in Tehran and a number of issues related to the security of two countries were discussed, sources privy to the meeting said.

In a joint statement issued at the end of Janjua's visit, both Tehran and Islamabad had announced to evolve an institutional mechanism such as the establishment of a joint commission to look after the border security management.

In the same statement, Pakistan and Iran had also called for unity among the Muslim Ummah and earliest resolution of conflicts between Muslim states.