Five countries from Oceania have announced participation in GREEN×EXPO 2027 (the 2027 International Horticultural Expo) as of 9 September 2026. The count comes from the lists published by the GREEN×EXPO Association (formally the 2027 International Horticultural Expo Association, a public interest incorporated association) and Japan’s Ministry of Foreign Affairs.
Contract status
Palau is the only Oceania country to have signed an official participation contract (announced on 5 March 2026; signed on 22 December 2025). The other four have not announced a signing as of September 2026. No exhibit details have been made public for any of the five.
Country-by-country status (5 countries in Oceania)
Area, population, language and industry details for each country come from the basic data pages published by Japan’s Ministry of Foreign Affairs.
| Country | Official participation contract | Area | Capital | Population | Languages |
|---|---|---|---|---|---|
| Solomon Islands | Not signed as of September 2026 | 28,900 km² (about twice Japan’s Iwate Prefecture) | Honiara | 819,198 (2024, Asian Development Bank) | English (official), Pijin (common language) |
| Republic of Nauru | Not signed as of September 2026 | 21.1 km² (about the size of Tokyo’s Shinagawa Ward) | Yaren | 11,947 (2024, World Bank) | English (official), Nauruan |
| Republic of Palau | Signed 22 Dec 2025 (Association announcement 5 Mar 2026) | 488 km² (about the size of Japan’s Yakushima island) | Melekeok | 17,695 (2024, World Bank) | Palauan, English |
| Republic of Fiji | Not signed as of September 2026 | 18,270 km² (roughly the size of Japan’s Shikoku region) | Suva | 933,154 (2025, World Bank) | English (official), Fijian, Hindi |
| Federated States of Micronesia | Not signed as of September 2026 | 700 km² (about the size of Japan’s Amami Ōshima island) | Palikir | 113,160 (2024, World Bank) | English plus eight local languages |
Solomon Islands became independent from the United Kingdom on 7 July 1978 and is a constitutional monarchy. Its main industries are agriculture (copra and timber) and fishing, and its leading export destinations are China, Italy and Australia.
Nauru newly joined the list of participating countries in the Association’s update dated 9 September 2026, and is one of the smallest countries in the world. According to the Ministry’s basic data, its main industry is mining (phosphate), but the phosphate that was the country’s main source of foreign currency is largely exhausted and no other industry supports the economy.
The Japan office of the Nauru Tourism Office said in a post on X on 9 October 2026 that Nauru will exhibit at the expo. Its plan is a “Republic of Nauru Garden” set indoors with air conditioning, staffed by volunteers recruited through the Japan-Nauru Association; the September call closed at the end of the month, and a second round was offered on 28 October. Donors’ names will go on a plaque in the garden. The GREEN×EXPO Association has not yet published the garden’s location or size. Nauru’s National Day is Thursday 16 September 2027 (National Day schedule).
Palau became independent in 1994 under a Compact of Free Association with the United States and is a presidential republic. Tourism is the main industry: visitor numbers peaked at 164,000 in 2015, fell sharply during the pandemic, and have been recovering since 2022. In March 2024 the United States approved a further 20-year extension of its financial support under the Compact.
Fiji’s main industries are tourism, sugar and clothing. Suva hosts the headquarters of the Pacific Islands Forum and the University of the South Pacific, among other regional bodies, and Fiji is at the centre of regional cooperation.
Micronesia is a federation of four states: Yap, Chuuk, Pohnpei and Kosrae. Its main industries are fishing, tourism and agriculture. Like Palau, it has a Compact of Free Association with the United States, and in March 2024 the United States approved a further 20-year extension of its financial support.
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The full list of participating countries is also available on our feature page, “Participating Countries Guide”.