Iran's foreign minister urged India and Pakistan on Monday to exercise restraint as he arrived in Islamabad for a one-day visit, while the nuclear-armed rivals trade accusations over a deadly attack in disputed Kashmir.

Nuclear-armed foes Pakistan and India must exert "maximum restraint" and step back from the brink of war, UN chief Antonio Guterres urged Monday, as tensions between the South Asian neighbours soared.

Iran’s foreign minister is in Pakistan to try and mediate in the escalation between Islamabad and New Delhi after last month’s deadly attack on tourists in the Indian-controlled section of Kashmir.