Prime Minister Lee Hsien Loong left Singapore yesterday for a two-day visit to Bangkok to pay his respects to the late King Bhumibol Adulyadej at the Grand Palace.
The Thai monarch, who reigned for 70 years, died on Oct 13 at the age of 88. His death triggered an outpouring of grief in the kingdom of 68 million people.
The government has declared a one-year mourning period and asked the public to refrain from entertainment for 30 days.
During his visit, PM Lee will meet Thai Prime Minister Prayut Chan- o-cha to express his condolences.
He will be accompanied by Mrs Lee and officials from the Ministry of Foreign Affairs, said the Prime Minister's Office in a statement yesterday.
In a letter to General Prayut last week, PM Lee said Singapore would remember the role King Bhumibol played in fostering the enduring friendship between both countries.
"Throughout his long and benevolent reign, His Majesty King Bhumibol had profound compassion for his people, and ceaselessly dedicated himself to improving their well-being," he added.
Other Singapore leaders, including President Tony Tan Keng Yam and Foreign Minister Vivian Balakrishnan, also paid tribute to the late King last week, remembering him as someone who dedicated his life to improving the welfare of Thais.
Dr Tan said in an interview last week that the King was "well beloved by his people and for good reasons", pointing to numerous projects he started, such as in the areas of water management, that brought far-reaching benefits to Thailand.
Dr Balakrishnan, who was in Bangkok for the Asean-European Union Ministerial Meeting, wrote in a condolence book: "Singapore stands shoulder to shoulder with our Thai friends in this sad and difficult period."