SINGAPORE - Prime Minister Lee Hsien Loong has sent a congratulatory letter to his British counterpart Boris Johnson, who assumed office on Wednesday (July 24).

In his letter, a copy of which was released by the Ministry of Foreign Affairs on Thursday, PM Lee said that Mr Johnson's appointment came at a "pivotal moment of change, as the United Kingdom negotiates its future relationship with the European Union, and as countries everywhere strive to work out how they can coexist and cooperate in a new global environment".

Mr Lee added: "As we navigate these complexities, I look forward to the United Kingdom continuing to stand up for free trade, multilateralism and a rules-based international order."

He also said that this year was "particularly significant" for Singapore-UK relations, given that it marks the bicentenary of the arrival of Sir Stamford Raffles in Singapore, "which put Singapore on the course that has led us here today".

"Singapore is a steadfast partner of the United Kingdom, with close ties underpinned by deep historical links," Mr Lee wrote.

He said he looked forward to working with Mr Johnson on the further development of the Partnership for the Future, which was launched in January this year. The partnership, which Mr Lee said reflected the "comprehensive and growing relationship" between Singapore and Britain, focuses on future-oriented issues such as the digital economy, sustainable innovation, defence and security, as well as youth, education and culture.

PM Lee also said he hoped that Mr Johnson would "find a chance to visit Singapore and the region again in the near future".

Mr Johnson, a former London mayor as well as foreign secretary, succeeded Mrs Theresa May, who had held the post for three years.