India asked World Court judges on Monday to order Pakistan to stay the execution of convicted spy Kulbhushan Sudir Jadhav.
India argued in a preliminary hearing at the UN court, formally known as the International Court of Justice (ICJ), that Pakistan violated the Vienna Convention on Consular Relations by denying the condemned man access to legal and other assistance from India. Pakistan was to respond later Monday.
Monday's hearings focused on India's request for so-called "provisional measures" that can be granted at short notice to ensure a dispute between states does not deteriorate during full ICJ proceedings, which typically take several years.
At the core of the dispute is the fate of Kulbhushan Sudir Jadhav, a former Indian naval officer who was arrested in March 2016 in Balochistan.
According to Islamabad, Jadhav confessed to being tasked by India's intelligence service with planning, coordinating and organising espionage and sabotage activities in Balochistan "aiming to destabilise and wage war against Pakistan".
In April, a Pakistani military court sentenced him to death. No date was set for the execution. Pakistan has said Jadhav's conviction and sentence remain open to appeal.
India's representative at the ICJ hearing, Deepak Mittal, described the charges against Jadhav as "concocted" and his trial as "farcical."
The ICJ is the UN court for resolving disputes between nations, and its decisions are final and binding. However, it has no means to enforce rulings and they have occasionally been ignored.