SINGAPORE this week will host the first meeting of the Association of South East Asian Nations (ASEAN) and its dialogue partners to focus specifically on regional security issues, a subject which the body has avoided previously as too controversial. The meeting comes in the wake of warnings from Singapore's previous and present prime ministers about the dangers resulting from post-Cold War changes in relationships in Asia. Addresses in Shanghai by former prime minister Mr Lee Kuan Yew, and in Tokyo by his successor, Mr Goh Chok Tong, reflected Singapore's concern that the decreased presence of the United States in Asia, following the closure of its bases in the Philippines, could lead to threatening shifts in the regional balance of power. In these circumstances, Singapore is stressing the importance of this week's landmark meeting, which will bring together officials representing the six members of ASEAN, plus Australia, Canada, the European Community, Japan, New Zealand, South Korea andthe US. ASEAN comprises Brunei, Indonesia, Malaysia, the Philippines, Singapore and Thailand. In the past, efforts by Singapore and the Philippines to have security issues discussed have run into resistance from Indonesia and Malaysia. But the changed strategic outlook resulting from the end of the Cold War prompted ASEAN leaders to agree last year that the annual meeting of ASEAN foreign ministers and its seven dialogue partners could be used as a forum for discussions on security co-operation. In Singapore on Thursday and Friday, the senior officials will prepare an agenda for the foreign ministers' meeting - the ASEAN Post-Ministerial Conference - which will be held in July. The uncertainty about Cambodia's future, North Korea's nuclear ambitions and the claims of China, Vietnam and four other countries to the Spratly Islands are likely to be among key issues for discussion. The US, which will be represented by the new Assistant Secretary of State for East Asian and Pacific Affairs, Mr Winston Lord, said it was going to the meeting with an open mind to listen to the views of ASEAN. But Mr Lord has already raised some hackles among ASEAN officials by linking security to democracy and human rights at the opening of the 11th ASEAN-US dialogue meeting in Brunei on Saturday. ''We believe security involves more than just arms and alliances,'' he said. ''Democracy and human rights are components of a broader definition of security.'' Mr Lord was later reported to have given assurances that the US would not make the human rights issue an obstacle to closer co-operation with ASEAN.