Continued efforts to strengthen the relationship between Singapore and Indonesia are necessary in the current climate of global economic uncertainty, said Singapore President Halimah Yacob yesterday.

In affirming the "deep, long-standing and multi-faceted" relationship between the two countries that has spanned over 50 years, Madam Halimah highlighted several areas of cooperation, including the economy, human resource development and people-to-people ties.

"As good neighbours, our two countries have reaped opportunities and tackled challenges together," said Madam Halimah.

"In the midst of the global economic uncertainty and other challenges that we face today, it is all the more important for Singapore and Indonesia to work closely together for the mutual benefit of peoples from the two countries."

Madam Halimah, who is on a four-day state visit to Indonesia that began on Monday, was speaking at a joint press conference alongside Indonesian President Joko Widodo at the Istana in Bogor.

In his remarks, Mr Joko reaffirmed the close ties between both countries, and thanked Singapore for its commitment to investing in Indonesia, including in infrastructure. He noted that cooperation also extended to education and research and development.

"It is my commitment to continue strengthening cooperation with Singapore," Mr Joko said.

Earlier in the day, Madam Halimah laid a wreath at the Kalibata Heroes' Cemetery, as is customary for state visits, before receiving an official welcome from Mr Joko.

Both presidents then planted a resin, or damar tree, in the Istana courtyard to symbolise the strong and healthy state of Singapore-Indonesia relations, before their bilateral meeting.

The leaders also witnessed the inking of an updated Avoidance of Double Tax Agreement (DTA) by Second Finance Minister Indranee Rajah and Indonesian Finance Minister Sri Mulyani Indrawati.

Madam Halimah noted that the updated tax agreement reflects how there is still room for the Singapore-Indonesia economic partnership to be strengthened.

The updates to the agreement, which first came into force in 1991, will lower the withholding tax rate for royalties and branch profits.

Singapore and Indonesia share close trade and investment ties, with bilateral trade amounting to $65 billion in 2018, a 9.4 per cent increase from the year before.

"Singapore has been Indonesia's top foreign investor for the past six years. This demonstrates Singapore's confidence in Indonesia's vibrant economy," said Madam Halimah, adding that the updated pact will benefit businesses.

Both sides look forward to the early ratification of the DTA, as well as the bilateral Agreement on the Promotion and Protection of Investments signed in 2018, Singapore's Ministry of Foreign Affairs (MFA) said. During their meeting, the leaders also discussed the potential for cooperation in areas such as the digital economy.

President Halimah highlighted the excellent partnership in human resource development, seen in the establishment of the Kendal Polytechnic to train workers for the Kendal Industrial Park, a 2,700ha joint venture between Singapore and Indonesia.

Cooperation between the countries' security agencies is also constantly being upgraded, she said, noting how closely they work to combat smuggling and other crimes.

On Monday, Singapore's Police Coast Guard and Indonesia's Directorate-General of Customs and Excise signed a memorandum of understanding that will provide for information exchanges and regular joint operations, patrols and bilateral training initiatives.

Madam Halimah added that strong cultural, educational and people-to-people ties anchor the relationship between the two countries, and cited efforts by the National Youth Council to partner groups in Indonesia to bring youth from both neighbours together.

Both leaders also discussed Singapore's ongoing efforts to deepen cooperation with Indonesia's regions.

President Joko and First Lady Iriana also hosted a state banquet lunch in honour of President Halimah and her husband, Mr Mohamed Abdullah Alhabshee.

Madam Halimah said: "This state visit underscores Singapore's firm commitment to working closely with Indonesia to create new economic synergies, strengthen political and defence relations, and deepen people-to-people ties."

In the afternoon, she also met Vice-President Ma'ruf Amin. MFA said they had a good discussion about the importance of education and vocational training in promoting human resource development.

They also exchanged views on building cohesive and harmonious societies, and agreed that Singapore and Indonesia could step up cooperation in this area, including through interfaith dialogue.