Tonga: Background and Issues for Congress
Overview
The Kingdom of Tonga is one of the United States' oldest diplomatic partners in the Pacific Islands region. U.S. policymakers, including some Members of Congress, have identified U.S. national security interests in Tonga and the Pacific, including maintaining free and open waterways; supporting U.S. diplomatic engagement; providing assistance in areas such as economic development, sustainable fisheries, and climate change; and maintaining strong economic and security ties with the region. U.S. policymakers have sought to bolster diplomacy; increase U.S. assistance in areas such as sustainable fisheries and economic development; and counter growing economic, political, and security engagement by the People's Republic of China (PRC, or China).
With approximately 100,000 inhabitants, Tonga is the last remaining monarchy in Polynesia and the only Pacific Islands country (PIC) never colonized by European powers. Tonga signed a protectorate agreement with the British Empire in 1900 and became independent in 1970. In the defense sector, Tonga is one of three PICs, along with Fiji and Papua New Guinea, to have a standing military.
Politics, Society, and Economy
Tonga is a constitutional monarchy with a unicameral Legislative Assembly. In 2010, the Legislative Assembly adopted constitutional reforms to broaden the number of popularly elected parliamentarians from nine to 17, with nine seats reserved for nobles selected by their peers. Previously, most of the 26 members of parliament were appointed by the monarch or were designated noble seats. The prime minister, Dr. 'Aisake Valu Eke as of 2025, is selected by the Legislative Assembly and is responsible for most government functions. The next general election for parliament is scheduled to be held in November 2025.
The monarchy retains substantial powers, including the authority to dismiss parliament, appoint and supervise the judiciary, and approve changes to the constitution. The current monarch, King Tupou VI, acceded to the throne in 2012. In August 2025, parliament passed legislation, with little opportunity for public consultation, renaming the Ministry of Foreign Affairs "His Majesty's Diplomatic Service" and placing it under direct crown oversight. Some democratic activists have expressed concerns that the king's actions portend democratic backsliding in Tonga.
The World Bank considers Tonga a lower-middle-income country. Its primary economic sectors include agriculture, fisheries, and tourism, all of which are vulnerable to climate-related events. About 40% of Tonga's total land area is used for agriculture, and the sector employs one-third of the labor force. Top aid donors include Australia and Japan, as well as multilateral donors such as the International Monetary Fund, the World Bank, and the Asia Development Bank. The Tongan economy relies on small-sum remittances from the Tongan diaspora; in 2023, remittances comprised over 50% of Tonga's total gross domestic product (GDP).
Tonga's military force, His Majesty's Armed Forces (HMAF), has land and naval components. The monarch commands the HMAF but under the constitution cannot "make war without the consent of the Legislative Assembly." The HMAF is small, with 590 personnel including support staff, and is focused on humanitarian assistance and disaster relief (HA/DR); search and rescue; countering illegal, unreported, and unregulated fishing (IUU); and delivery of supplies to Tonga's outer islands.
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Figure 1. Tonga at a Glance |
U.S.-Tonga Relations
The State Department has described U.S.-Tonga relations as "broad and deep, based on shared values and close cooperation." In 2023, the United States established an embassy in Nuku'alofa, Tonga's capital. In August 2024, the U.S. embassy opened a consular window pilot program to support visa services.
The United States provides military assistance to the HMAF and includes Tongan forces in joint military exercises, including Pacific Partnership, U.S. Indo-Pacific Command's largest annual multinational HA/DR mission. The Nevada National Guard has a State Partnership Program with the HMAF that includes joint trainings to build partner capacity and interoperability. Tonga and the United States have a shiprider agreement that allows Tongan law enforcement officials to embark on U.S. Navy and Coast Guard ships in order to board and search vessels suspected of violating Tongan laws and to combat IUU fishing in Tonga's territorial waters. Tonga is also a party to the South Pacific Tuna Treaty, which provides U.S. fishers access to the waters of treaty signatories in exchange for economic assistance. (The treaty was updated in 2016. In the 119th Congress, the House-passed, Senate pending H.R. 531 would reflect those updates in U.S. law.)
In the past, U.S. development assistance to Tonga support included the Pacific American Fund, climate-ready projects (2016-2021), and the Institutional Strengthening in Pacific Island Countries to Adapt to Climate Change program (2015-2021). Following a volcanic eruption in 2022, USAID provided $2.6 million in humanitarian assistance and partnered with local organizations on disaster risk reduction. U.S. programming also addressed health challenges and democracy and governance.
Current development support includes the U.S. Peace Corps presence in Tonga, which dates to 1967 and focuses on education and the environment. In 2025, the U.S. Millennium Challenge Corporation selected Tonga to receive threshold program assistance to address constraints on economic growth, citing the government's reforms to increase economic growth and private investment.
The Tongan diaspora in the United States is concentrated in Hawaii, California, Utah, and Washington and serves as a significant remittance source for Tonga. The United States has deported convicted felons of Tongan nationality back to Tonga after they served their terms in American prisons. Prime Minister Eke has expressed concern that the Trump Administration's deportation policies could strain Tonga's capacity to reintegrate deportees.
Tonga-China Relations
Tonga adheres to a "One China Policy" and maintains official diplomatic relations with China. The Tongan government is facing a substantial debt service burden through 2028 on account of repayment deadlines to PRC entities, which own two-thirds of Tonga's $195 million debt. Currently, Tonga's annual repayments to China are near 4% of GDP and threaten to derail public services and climate priorities. PRC development and infrastructure projects in Tonga include agricultural investments, wind farm development, and small public welfare projects such as water tanks and fishing boats. In May 2022, PRC Foreign Minister Wang Yi met with King Tupou VI and the former prime minister in Tonga and reportedly discussed Tonga's debt to China's Export-Import Bank.
A delegation from the PRC Ministry of Public Security visited Tonga in April 2024, ahead of the Pacific Islands Forum Leaders Meeting (PIFLM), and offered security support to Tonga, the PIFLM host, during the event. (China is a dialogue partner, but not a member, of the Pacific Islands Forum). Former Prime Minister Hu'akavameiliku responded to Australian and U.S. worries around PRC security engagements with the region by saying that "there's no reason to be concerned."
Environmental Policy and Natural Resources
Addressing climate change is a priority for the Tongan government, as the country—like other PICs—is vulnerable to natural disasters and environmental shifts. The effects of climate change on Tonga include temperature rise, shifts in rainfall patterns, rising sea levels, ocean acidification, and extreme weather events. In a 2023 speech to the United Nations, then-Prime Minister Hu'akavameiliku called for a climate-focused fund for the Pacific Islands. The World Bank is financing a Tonga Climate Resilience Project, which includes an upgrade of the international airport and construction of a new parliament building. Per the 2024 PIFLM, Tonga is slated to be home to a new Pacific Resilience Facility, which is to finance climate resilience initiatives in the region.
Tonga is one of several PICs that support seabed mining in areas beyond its national jurisdiction (ABNJ), and its Seabed Minerals Act authorizes the regulation of exploration and mining activities within Tonga's exclusive economic zone and ABNJ. (For more information, see CRS In Focus IF12974, Seabed Mining Interests Across the Pacific Islands, by Caitlin Keating-Bitonti and Jared G. Tupuola.) In August 2025, Tonga and The Metals Company (TMC), a Canadian seabed mining exploration company, updated a 2021 sponsorship agreement to TMC's subsidiary, Tonga Offshore Mining LTD. The updated agreement would support Tongan development priorities in exchange for Tonga's sponsorship of potential future TMC mining in the country's section of the Clarion Clipperton Zone, which is rich in seabed critical minerals.
Considerations for Congress
U.S.-Tonga diplomatic relations expanded over the past decade as U.S. Administrations took a greater interest strategic competition in the Pacific. Congress may exercise oversight of U.S. foreign policy toward Tonga and shape pertinent funding priorities. Tonga and other PICs have noted U.S. efforts to re-engage the Pacific and appear to desire durable commitments in the form of programs and investments. Some Members of Congress have expressed support (e.g., S.Res. 611 in the 116th Congress) for Tonga's democratic progress and may continue to support such efforts, including as a means of strengthening U.S. regional interests. However, should monarchical power erode democratic processes, some Members may seek to place restrictions on U.S. support to Tonga. Additional questions facing Congress may include the following:
What are the implications of U.S. foreign assistance reorganization on U.S.-Tonga relations?
How might Tonga's diplomatic reorganization impact U.S.-Tonga bilateral engagement?
What are the implications of U.S. deportations of Tongan nationals back to Tonga on bilateral relations?
What opportunities exist for U.S.-Tongan cooperation on seabed mining? Are their adverse impacts of U.S. support to Tonga's seabed mining industry with the broader Pacific?