The leaders of Thailand and Cambodia met in Indonesia on Sunday to discuss their bitter border dispute, which has overshadowed an annual summit of regional leaders, officials said.
Cambodian Prime Minister Hun Sen sat down with Thai Prime Minister Abhisit Vejjajiva and Indonesian President Susilo Bambang Yudhoyono, whose country currently chairs the Association of Southeast Asian Nations (ASEAN).
The unscheduled meeting took place a day after Hun Sen took aim at his Thai counterpart in the closed-door opening session of the two-day summit in Jakarta, according to a transcript of his comments released to reporters.
Hun Sen admitted after Sunday's meeting that the row was "spoiling" the Southeast Asian summit, which was supposed to focus on efforts to create a harmonised regional economic community by 2015.
"Everyone knows that the problem of the Thai-Cambodia border has been spoiling the atmosphere and also creates a challenge for ASEAN," he told a press conference after the meeting.
In a highly critical tone not usually heard at ASEAN meetings, the Cambodian leader on Saturday accused Thailand of invading its neighbour and seeking to prolong the conflict "in order to violate weaker neighbouring ASEAN members".
"The invasion of the Thai troops of Cambodia's territory resulted in a series of clashes and eventually a large-scale war from the 4th to the 7th of February, 2011," he told the assembled leaders.
Around 18 people have been killed and 85,000 have been temporarily displaced in weeks of clashes over ownership of a small patch of territory surrounding an 11th-century Khmer temple. The temple itself belongs to Cambodia.
Indonesia has been trying to mediate a solution to the conflict on behalf of ASEAN, but so far it has achieved little except an in-principle agreement from both sides to accept a small team of military observers on the border.
Abhisit responded to Hun Sen's criticism by saying he was ready for dialogue and insisting that the matter be resolved bilaterally.
"Thailand has no intention whatsoever to have conflicts. I am therefore disappointed that Prime Minister Hun Sen has stated otherwise regarding Thailand's intentions," he told the leaders Saturday, according to a copy of his remarks released to the media.
He also agreed that the dispute, which was not on the formal agenda of the ASEAN summit, threatened to undermine the credibility of the 10-nation group's plans to create an integrated economic zone by 2015.
"I accept that the issue could affect the credibility of ASEAN. We must therefore make sure that any problem should be solved, locally, bilaterally and if needed with the facilitation of the region," he said.
"Thailand recognises full well that any conflict between ASEAN member states can undermine ASEAN's community-building efforts."
Officials said the two leaders agreed to have their foreign ministers meet again to discuss the conflict further.
ASEAN Secretary General Surin Pitsuwan said: "The fact that they are meeting is a good sign".