Small island states share many common interests and concerns and, thus, have to "make common cause together", said Prime Minister Lee Hsien Loong.

Mr Lee said that Singapore and Pacific Island countries are fellow small island states with shared concerns such as defence, climate change and having to adapt to the changing external environment.

He was at a dialogue that Asia-Pacific Economic Cooperation (Apec) leaders had with leaders from Pacific Island states yesterday.

While many Pacific Island countries are not part of the 21-member Apec grouping, the Pacific Islands Forum secretariat is an observer, and leaders and ministers from its countries are in Port Moresby, Papua New Guinea, this week for meetings with Apec leaders.

Noting the value of yesterday's dialogue, Mr Lee said that is why Singapore set up the Forum of Small States at the United Nations in 1992, to "advocate for our collective interests".

He added that the Republic regularly attends the annual leaders summit by the Pacific Island Forum, which comprises 18 members including Australia and Fiji.

Singapore is also a member of the Small Island Developing States grouping, he said.

Building relationships with Pacific Island states also provides opportunities for Singapore to share its developmental experience, Mr Lee said, adding that nearly 5,000 officials from these states have visited the Republic over the years.

The dialogue's theme, "Partnering for an Inclusive Digital Future", is timely as digital links can overcome geographical limits and facilitate economic growth without a lot of natural resources or space, Mr Lee said.

"However, to harvest the full benefits of the digital economy, we need to continue investing in infrastructure and educate our people so that we can connect together."

Mr Lee had earlier attended the welcome ceremony for the Apec summit, and participated in a dialogue between Apec leaders and businessmen on the Apec Business Advisory Council. He joined the other leaders for a gala dinner yesterday evening, and will take part in the Apec leaders' retreat today before flying back to Singapore.

The council had presented a report to the leaders with three broad recommendations. First, that Apec leaders continue to support the international trading system, and head off rising trade tensions.

It also called for greater efforts in explaining the benefits of free trade to their people, and for Apec economies to adopt rules that enable their business communities to operate successfully in the digital age.

Singapore Business Federation chief executive Ho Meng Kit and CrimsonLogic chief executive Saw Ken Wye represented Singapore at the business leaders' dialogue.

On Apec's relevance to Singapore businesses, Mr Ho noted that local companies trade and invest mostly in the Asia-Pacific region.

And preserving an environment where markets are open and friendly to investors, with transparent and modern rules, is definitely good for businesses, Mr Ho said.