Tonga needs to find US$16,444 to regain its right to vote at the United Nations.
The amount, equivalent to TP$ 37,751.60, is needed to reduce the amount Tonga owes to the international body to an acceptable level.
Tonga is one of seven countries that have lost their voting rights.
The others are Venezuela, Lebanon, Central African Republic, Gambia, Lesotho and Yemen.
Comoros, Sao Tome and Principe, and Somalia are also in arrears but UN said it will keep their voting rights until September.
Details of the kingdom’s full debt have not been released.
Countries whose debt to the UN equals or exceeds the amount of the contributions due from it for the preceding two full years lose their vote.
Only 146 of the 193 member states paid their dues in full for the 2019 budget.
Last October UN Secretary-General Antonio Guterres said the organisation was facing a serious financial crisis.
King Tupou VI addressed the UN General Assembly last year and said the kingdom looked to the Security Council to provide protection from threats to international peace and security.