Pakistan and India failed to resolve a border dispute over a river estuary during talks on Friday, despite the "successful completion" of a joint survey.
The nuclear-armed neighbours conducted the survey of the Sir Creek estuary earlier this year, and officials discussed the results during a two-day meeting in Rawalpindi.
"They exchanged maps/charts showing their respective positions on the delineation of the boundary in Sir Creek and delimitation of the maritime boundary," Pakistan's Foreign Office said in a statement after the talks.
The dispute over the 100 kilometre long estuary has hampered exploration for oil and gas and led to the detention of hundreds of fishermen from the two countries, mostly in areas where demarcation is unclear.
"The two sides agreed to continue discussions for amicable settlement of the issue," the statement said.
Pakistan and India have fought three wars and came dangerously close to a fourth one in 2002.
But ties between the South Asian neighbours have warmed since they began a peace process in 2004, although progress has been slow on their territorial disputes, of which the Himalayan region of Kashmir is by far the most serious.