The delegations, led by Indian Defence Secretary Aji Vikram Singh and his Pakistani counterpart Tariq Waseem Ghazi, met for three hours in the opening session in a "cordial and friendly atmosphere," an official statement said.

"Ideas were exchanged by both sides for a peaceful resolution of the Siachin dispute," foreign ministry spokesman Jalil Abbas Jilani told AFP, without elaborating.

The talks, part of a general diplomatic thaw between the nuclear-armed South Asian neighbours, were to resume Friday and lead to a joint statement.

Pakistani officials earlier said they would push for a troop withdrawal from the 21,000 foot (6,300 metre) high glacier at the borders of India, Pakistan and China, to positions held more than three decades ago.

The dispute over Siachen has left more soldiers dead from extreme cold than from bullets. Analysts say it lost its strategic value when India and Pakistan became nuclear powers in 1998.

India's Singh sounded a note of optimism on his arrival late Wednesday for the talks, which were held in the garrison town of Rawalpindi, near the capital Islamabad.

"We have been given directions by our respective political leadership to move ahead," he told reporters. "We have come with an open mind and ... the atmosphere is definitely positive."

When Pakistan's President Pervez Musharraf met Indian Prime Minister Manmohan Singh last month, the two sides pledged to find a solution to the Siachen row.

Pakistan wants to see implemented what it says was an understanding reached in 1989, under which soldiers from both sides would pull back to where they were at the time of the signing of a historic 1972 agreement.

Musharraf said in an interview published this week that India "backtracked" on the deal when both countries' defence secretaries met in New Delhi in 1992, but added that he believed the two sides would be able to end the stand-off.

A senior Pakistan foreign ministry official said it would "not be acceptable to Pakistan in any case" if India, which occupied most of the ice field in 1984, wanted to maintain its troops' positions.

India and Pakistan have rowed over Siachen since 1948 and the first of their three wars, when a ceasefire line was drawn in Kashmir up until a reference point known as NJ 9842.