Chinese President Xi Jinping and leaders of the ruling Communist Party gathered at a reception on Sunday (Sept 30) by the State Council to mark the 69th anniversary of the founding of the People's Republic of China.

China officially celebrates its national day on Monday, and Singapore's President Halimah Yacob and Prime Minister Lee Hsien Loong are among the world leaders who have written to Chinese leaders to convey congratulatory messages.

Both Madam Halimah and Mr Lee reaffirmed Singapore's strong ties with China and emphasised Singapore's commitment to free trade.

In her letter to Chinese President Xi Jinping, President Halimah said that China's commitment to the path of economic growth and liberalisation amid global uncertainties will not only contribute to China's future progress but also boost global trade and development.

China's Belt and Road Initiative (BRI), which enhances connectivity and linkages, has also reached a significant five-year milestone this year, said Madam Halimah. The initiative "has promoted the spirit of common prosperity and brought countries closer together", she added.

This year marks the 40th anniversary of the opening up of China.

Noting that Singapore-China relations are excellent and have evolved over time, Madam Halimah said: "Over the years, the cooperation between our two countries has grown beyond the traditional areas of trade and investment to cover new areas including the Belt and Road Initiative, finance, and legal and judicial issues."

She said the China-Singapore (Chongqing) Connectivity Initiative, which includes the Southern Transport Corridor, has added further impetus to the two countries' BRI cooperation by linking the "Belt" and the "Road" as well as strengthening connectivity between China and Asean.

"As beneficiaries of free trade, our two countries are also working towards the completion of a substantive and high standard upgrade of the China-Singapore Free Trade Agreement by the end of the year," said Madam Halimah.

As Asean chair this year, "Singapore will continue to work with our dialogue partners including China and enhance cooperation to build a resilient and innovative Asean", the president said.

"We are working together on a substantive and mutually beneficial Regional Comprehensive Economic Partnership. Together, we can send a strong signal of our joint commitment to free trade and a rules-based multilateral trading system."

In his letter to Chinese Premier Li Keqiang, PM Lee said that amid "an increasingly uncertain global environment and growing protectionism, China's continued support for trade liberalisation and economic integration will benefit China and the global economy".

Noting Singapore's strong and multi-faceted relations with China, Mr Lee said that since Chinese late leader Deng Xiaoping's visit to Singapore 40 years ago, cooperation between both countries has broadened and deepened immensely.

"Besides our three Government-to-Government projects, we are expanding cooperation in new areas such as innovation and technology, sustainable development, financial services, and legal and judicial cooperation," Mr Lee said.

"Our cooperation under the Belt and Road Initiative has progressed well and now spans infrastructure connectivity, financial connectivity, third party cooperation and training, and professional services," Mr Lee added.

As the Asean-China Coordinator for the last three years, Singapore has worked with China and the other Asean member states to foster Asean-China ties.

"We look forward to celebrating the 15th anniversary of the Asean-China Strategic Partnership and setting the Asean-China 2030 Vision Statement at the Asean Summit in Singapore this year," said Mr Lee.

Singapore and China have also worked closely to advance their shared interest in promoting free and open trade. Mr Lee said Singapore looks forward to an early conclusion of the Regional Comprehensive Economic Partnership, and a substantial upgrade of the China-Singapore Free Trade Agreement during Mr Li's official visit to Singapore in November.

Mr Lee wished Mr Li good health and continued success.

Madam Halimah wished China continued peace, stability and prosperity. She also wished Mr Xi continued good health and success.