Deputy Prime Minister Teo Chee Hean, who is on a two-day working visit to Hong Kong, met the city's Chief Executive Leung Chun Ying yesterday, Singapore's Ministry of Foreign Affairs said in a statement.
During the meeting, DPM Teo congratulated Mr Leung on his recent appointment as vice-chairman of the Chinese People's Political Consultative Conference.
Mr Teo, who is also Coordinating Minister for National Security, and Mr Leung "reaffirmed the longstanding friendship at all levels between Singapore and Hong Kong", the ministry said.
They also expressed appreciation that officials from both sides continue to have frequent exchanges to share experiences over the years.
Mr Teo was also hosted to lunch by incoming Chief Executive Carrie Lam.
He congratulated Mrs Lam on her recent electoral success, and they exchanged views on developments in Singapore, Hong Kong and the region.
Mr Teo also expressed confidence in Hong Kong's future development and reaffirmed Singapore's commitment to build upon the strong bilateral cooperation in areas including the public service, housing, transport, culture and education.
He also extended an invitation to Mrs Lam to visit Singapore soon.
The ministry statement added: "DPM Teo said that the stability and prosperity of the Hong Kong SAR is best assured under the 'One Country, Two Systems' framework as an integral part of China.
"This arrangement is beneficial to Hong Kong SAR and China."
In addition to building on its extensive international links and advantages, Hong Kong can benefit from its integration with the Pearl River Delta region and the development of the Guangdong-Hong Kong-Macau Big Bay area, the statement said.
Today, Mr Teo will have separate meetings with former chief executive Tung Chee Hwa and Hong Kong business leaders to exchange views on developments in the city and across the region.
Mr Teo will also meet the Singaporean community in Hong Kong at a dinner reception.