Pakistan has cancelled a conference of lawmakers from Commonwealth countries after a feud with India over Kashmir.
India demanded that lawmakers from Indian-administered Kashmir be included at the event, Pakistan National Assembly speaker Ayaz Sadiq said.
More than 50 countries were expected to participate at the conference in Islamabad on 30 September.
Kashmir, claimed by both countries in its entirety, has been a flashpoint for more than 60 years.
Pakistan does not recognise the Indian state government in Kashmir, and had not invited the speaker of the assembly government.
The South Asian rivals have fought two wars over the region. A ceasefire agreed in 2003 remains in place, but the neighbours often accuse each other of violating it.
Thursday's decision to call off the Commonwealth parliamentary conference came as security advisers from Pakistan and India - Sartaj Aziz and Ajit Doval - prepared to meet in Delhi on Sunday to discuss a range of issues aimed at easing tensions.
On Thursday, Indian authorities detained and later released two Kashmiri separatist leaders, while a third remained under house arrest.
Pakistan's foreign ministry spokesman Qazi Khalilullah was quoted by the Associated Press news agency as saying he expects India will allow national security advisor Sartaj Aziz to meet with the Kashmiri leaders during his visit to Delhi.
He said the separatist leaders were "important stakeholders'' in efforts to find a peaceful solution.
In August last year India cancelled talks with Pakistan after Pakistan's high commissioner in Delhi consulted Kashmiri separatist leaders ahead of the talks.