Iranian President Hassan Rouhani urged Pakistan Prime Minister Imran Khan to take action against the al-Qaeda linked Jaish ul-Adl terrorist group.
This comes after tensions between Iran and Pakistan escalated last month following the deadly attack on a bus carrying Islamic Revolutionary Guard Corps (IRGC) servicemen, which killed as many as 27 and left 13 others wounded.
Two Pakistani nationals were suspected of involvement in the crime. Jaish ul-Adl had claimed responsibility for the ghastly attack which happened on a highway in eastern Iran near the Pakistani border.
Mr Rouhani said that Iran and Pakistan should not allow decades of friendship and fraternity between the two countries to be affected by the actions of small terrorist groups, the source of whose financing and arms is known to both the sides.