THE HAGUE (Reuters) - India asked World Court judges on Monday to order Pakistan to stay the execution of an Indian citizen who Islamabad says is a captured spy, a case that has escalated tensions between the two nuclear-armed neighbors.

India argued in a preliminary hearing at the U.N. 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 responded that the court should decline jurisdiction in the case.

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 officer in the Indian navy who was arrested in March 2016 in the Pakistani province of Baluchistan. There has been a long-running conflict in Baluchistan between Pakistani security forces and a militant separatist movement.

According to Islamabad, Jadhav confessed to being tasked by India’s intelligence service with planning, coordinating and organizing espionage and sabotage activities in Baluchistan “aiming to destabilize 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.”

Responding, Pakistan’s agent before the court, Mohammad Faisal, said India’s complaint was “political theater” and the court “should not exercise any jurisdiction in the case”.

Pakistan argued that counsular access is not an absolute right under the Vienna treaty, and that a 2008 bilateral treaty between India and Pakistan supersedes it anyway.

The court said it would set a date for ruling “as soon as possible”.

The ICJ is the U.N. court for resolving disputes between nations, and its decisions are final and binding. However, it has no means to enforce its rulings and they have occasionally been ignored.

In a similar dispute over the Vienna Convention in 1999, the ICJ ordered the United States not to execute a German national who did not get proper consular assistance, but the man was put to death regardless.

After a 2004 ruling against the United States in a case brought by Mexico, the administration of then-President George W. Bush ordered reviews of dozens of cases of Mexicans on U.S. death row who had not been offered consular access as a remedy.

The U.S. Supreme Court later ruled that under the U.S. federal system, individual states are not obliged to comply with the international treaty, a contradiction that has yet to be resolved.