SINGAPORE - Prime Minister Lee Hsien Loong has written a valedictory letter to Mr Dmitry Medvedev, who stepped down as Russian Prime Minister last week, and congratulated Mr Mikhail Mishustin on taking over the post, Singapore's Ministry of Foreign Affairs said in a statement.

In the valedictory letter released by the ministry on Tuesday (Jan 20), Mr Lee extended his best wishes to Mr Medvedev on his new appointment as Deputy Chairman of Russia's Security Council.

"Relations between Singapore and Russia grew steadily under your leadership," Mr Lee noted in the letter, adding that many of the achievements were reached through the annual High-Level Singapore-Russia Inter-Governmental Commission over the past decade.

Both countries had made significant progress in expanding their collaboration to include new areas such as innovation and the digital economy, Mr Lee said.

He said a major milestone for the two countries was the signing of the free trade agreement in October last year between Singapore and the Eurasian Economic Union (EAEU), of which Russia is a member.

"I wish you continued good health and every success in your new appointment," Mr Lee added.

In his letter congratulating Mr Mishustin, Mr Lee lauded the relations between Singapore and Russia, which he said are "strong and on an upward trajectory".

Mr Lee said both sides had expanded their economic relations through the EAEU trade agreement since the state visit of President Vladimir Putin to Singapore in 2018.

He added that the annual High-Level Singapore-Russia Inter-Governmental Commission remained an important institutional pillar to consolidate bilateral ties and pursue new areas of cooperation, including in areas such as innovation and the digital economy.

"I look forward to working with you to further strengthen our relationship, and wish you success in your appointment," Mr Lee said.

Mr Medvedev, a 54-year-old former president, last Wednesday announced his resignation and that of his government to allow Mr Putin to carry out changes to the Constitution that would strengthen Parliament's role.

Mr Mishustin, 53, who ran the country's tax service, was appointed the Prime Minister a day later after being nominated for the post by Mr Putin.