Ahead of the 6th Asean Defence Ministers' Meeting (ADMM) Retreat and the 6th ADMM-Plus on Monday, Thailand on Sunday signed a joint vision statement on defence with the US and memorandums of understanding (MoUs) on defence cooperation with Japan and China.
Sources said issues discussed at the meetings included the South China Sea dispute and Rohingya crisis, although no details of their debates or decisions emerged.
Signed by Prime Minister and Defence Minister Prayut Chan-o-cha and US Secretary of Defence Mark Esper, the Thai-US Joint Vision Statement 2020 recognised the importance of sustained security cooperation, including education and training, capacity-building, interoperability and modernisation of defence and security institutions to strengthen the Thai-US defence alliance.
Under this statement, both sides also recognise and seek to maintain Asean centrality and the important role of Asean-led regional security architecture in promoting mutual trust and confidence-building for regional peace and stability.
The nations reaffirm the importance of the US-Thailand defence treaty alliance for the 21st century and note that defence ties complement all elements of their much broader relationship, including strong diplomatic, economic and cultural ties.
They also committed to strengthening all these important partnerships in order to achieve greater peace in the Indo-Pacific region and beyond.
Under the Thai-Chinese MoU, signed by Gen Prayut and Chinese Defence Minister Gen Wei Fenghe, the two countries agreed to work together to promote their defence cooperation through various activities including visits, training and studies, intelligence liaison, news and information sharing and military capacity building, said Defence Ministry spokesman Lt Gen Kongcheep Tantravanich.
China also pledges full support to Thailand's economic development, said Lt Gen Kongcheep, relaying a message Gen Wei shared with Gen Prayut at the ceremony.
Gen Wei also emphasised to Gen Prayut that the main objective of China's One Belt, One Road policy is to ensure all countries will benefit, said Lt Gen Kongcheep.
Previously on Saturday night, Gen Wei had informally discussed with navy chief Adm Luechai Ruddit a proposal for Thailand and China to initiate a joint naval exercise, said Adm Luechai.
In a similar MoU signed by Gen Prayut and Japanese Defence Minister Taro Kono, the countries agreed to exchange military visits, military news and information, views and knowledge on several levels, said Lt Gen Kongcheep.
Both sides also agreed to step up defence cooperation through joint exercises; studies and research; deployment of maintenance forces and military equipment and technology; and development of the defence industry, he said.
Japan is determined to cement relations with Thailand and adopt the United Nations Security Council's resolutions on irreversible denuclearisation and missile test control, said Lt Gen Kongcheep relaying a message Mr Taro told Gen Prayut at the signing.
Deputy Prime Minister Prawit Wongsuwon, meanwhile, underlined during an informal session the importance of strengthening regional defence cooperation to keep up with the fast development of technology.
As technology development connects the countries up more closely and spurs development in other areas, at the same time it leaves the door wide open to transnational criminals and terrorists, said Gen Prawit.
The region's security environment is changing rapidly and new forms of security threat are emerging, he said, adding that this underlines the importance of adjusting the region's defence cooperation.
In a meeting with Russian deputy minister of defence Alexander Fomin, both countries appreciated their cooperation in national defence as well as military medical centres and humanitarian assistance development, Lt Gen Kongcheep said.
Singapore Defence Minister Ng Eng Hen said he appreciated the joint military practices and was ready to support Thailand in working on marine security, the general said.
Australian Defence Minister Linda Reynolds also hailed cooperation with the Asean regional grouping especially on marine security and anti-terrorism, Lt Gen Kongcheep said.