Pronouncing the World Court's verdict, ICJ Judge Ronny Abraham of France said Pakistan should have given India consular access to its national Jhadav as per Vienna Convention.
As a rare case, India approached the ICJ, seeking relief in the form of immediate suspension of the death sentence and a declaration that the sentenced handed to Mr. Jadhav was in defiance of rights defined by the Vienna Convention and in violation of basic human rights.
It said Pakistan should ensure that no execution takes place until the final hearing by the court and that Pakistan shall inform the court of all measures taken in implementation of the final order.
Outlining the reasons for its decision, Abraham said Pakistan had "given no assurances" Jadhav would not be executed before the court delivered its final decision.
Hailing the verdict, India's Attorney General Mukul Rohatgi said it is a victory for India's stand.
India on May 8 sought the worldwide court's intervention to annul the death sentence given by a Pakistan military court to Jadhav who Islamabad says was arrested in Balochistan on charges of spying, sabotage and terrorism.
On May 8, India had dragged Pakistan to the ICJ for refusing consular access to Jadhav and for violating the Vienna Convention on consular relations.
Overruling Pakistan's contention that ICJ has no jurisdiction over the matter, an eleven-member bench said that it has prima facie jurisdiction in the case after Pakistan's failure to give consular access to India.More news: US Falls to Finland, 2-0, in MWC Quarterfinals
The Hague-based court ordered Pakistan on Thursday to stop the 46-year-old former Indian naval officer's execution until the judgment is out.
"I personally was very relieved and I'm sure every Indian is relieved to hear this order", Indian Ministry of External Affairs spokesman Gopal Baglay said.
"Without prejudging the result, the ICJ considers that the risk or irreparable prejudice, the mere fact that Jadhav is under such a sentence and might be executed, is sufficient to demonstrate such a risk".
However, Pakistan said that it had arrested Kulbhushan from Balochistan only and recovered a passport from him which described him as a Muslim man. The Court has jurisdiction in the case because of the Vienna Convention and dismisses Pakistan's reservations on this issue. But Pakistan would be hard put to flout the interim order.
The ICJ was set up in 1945 to rule on disputes between nations in accordance with worldwide law.
The verdict makes this one of the biggest diplomatic victories for India on the global stage.
India has strongly contradicted the statement by Pakistan and asked the ICJ to cancel the death sentence on Kulbhushan. The court stayed the execution of Kulbhushan till its final verdict. "The entire trial conducted in the military court is illegal", Choudhary told ANI.