The Pakistani side has sought fresh dates later this month or in June for talks on the Sir Creek issue, the sources told PTI.
The sources said fresh dates would be decided through diplomatic consultations. The reasons for Pakistan's decision could not immediately be ascertained.
Foreign Office spokesman Moazzam Khan had recently announced that representatives of the two countries would meet in New Delhi during May 14-16 to discuss the Sir Creek issue.
Some reports have suggested that Islamabad [ Images ] wants to assess progress on the Siachen issue before holding talks on Sir Creek.
The next round of talks on the military standoff on Siachen glacier is scheduled for mid-June.
Representatives from Pakistan's powerful military play a key role in talks on both Sir Creek and Siachen. Pakistan has considerably hardened its stand on the Sir Creek issue in recent months though the two sides had said they had made progress after a joint survey of the marshlands.
After 139 people were buried when an avalanche hit a high-altitude Pakistan Army [ Images ] camp in Siachen sector last month, several Pakistani leaders, including army chief Gen Ashfaq Parvez Kayani, have called for the demilitarisation of the glacier.
However, Kayani contended that India had hardened its position by seeking the demarcation of the Line of Control [ Images ] in the region.
Defence Minister A K Antony has said there is no change in India's stand on Siachen