Energy officials from India, Iran and Pakistan have failed to reach an agreement on a gas pricing formula for a multi-billion dollar joint pipeline project under consideration.

They met for two days in Islamabad and have agreed to meet again in July in New Delhi.

Iran first proposed the $7-billion project in 1996, but hostilities between India and Pakistan kept it dormant. 

Talks have revived as warming relations between the two countries in recent years have reduced India's fears about the 3,000 - kilometer pipeline's security in Pakistan.

The United States has long opposed the pipeline because its differences with Iran over that country's nuclear ambitions.

Some information for this report was provided by AP and Reuters.