Burma's prime minister has begun an official visit to Singapore as part of a tour of member states of the Association of Southeast Asian Nations, or ASEAN. ASEAN members have been unusually outspoken about Burma's continued detention of democracy activist Aung San Suu Kyi.

Burmese Prime Minister Khin Nyunt held talks Monday with his Singaporean counterpart, Lee Hsien Loong.

Singapore is the largest foreign investor in Burma, with more than $1.6 billion invested, and financial matters were expected to be a major topic of discussion.

Another matter thought to have been raised is the continued detention of Burma's leading opposition figure, the Nobel laureate Aung San Suu Kyi. She was detained in May of last year and remains under house arrest in Rangoon.

A statement Monday by the Singaporean Foreign Ministry provided little detail. It said there had been a "candid exchange of views on regional developments and trends" between the two prime ministers. It said Mr. Lee "expressed his understanding of the complex nature of Burma's challenges and problems."

The statement also said the talks highlighted "international and regional concerns about the situation in Burma" - an apparent coded reference to the lack of political reform inside Burma.

ASEAN member states - which include Burma and Singapore - usually refrain from commenting on each other's internal affairs. But members such as Thailand and Indonesia have been unusually outspoken in calling for Aung San Suu Kyi's release, and for general political reform in Burma.

Aung Zaw edits The Irrawaddy, an independent newspaper in Thailand devoted to Burmese issues. He says Singapore also appears to be more critical of Burma's military government than in the past.

In the past we know that Singapore was one of the strongest supporters of the military junta," he said. "(But) lately we have witnessed that Singapore has kept their distance from the military government and even the Singapore publications and newspapers have published articles criticizing the junta.

He said Aung San Suu Kyi's case is expected to be raised by Singaporean officials, but he said Khin Nyunt was likely to reply, as he has to other heads of government, that she will be freed "at the appropriate time."

Burma's domestic policies are not only affecting relations within ASEAN.

A meeting including EU and ASEAN leaders is scheduled in Vietnam for October 8th, but European governments have balked at attending a meeting with Burmese leaders while Aung San Suu Kyi remains in detention.