Sione Ngongo Kioa is a Tonga

Tonga

Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...

n diplomat

Diplomat

A diplomat is a person appointed by a state to conduct diplomacy with another state or international organization. The main functions of diplomats revolve around the representation and protection of the interests and nationals of the sending state, as well as the promotion of information and...

 and is currently the High Commissioner

High Commissioner

High Commissioner is the title of various high-ranking, special executive positions held by a commission of appointment.The English term is also used to render various equivalent titles in other languages.-Bilateral diplomacy:...

 of the Kingdom of Tonga to the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. He is also concurrently accredited as Ambassador Extraordinary and Plenipotentiary of Tonga to the Russian Federation, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, the Netherlands, Denmark

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

, Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, Luxembourg

Luxembourg

Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...

, Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

, Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, and the European Union

European Union

The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

.

After graduating from Tonga High School

Tonga High School

Tonga High School is a selective state-owned co-ed secondary school located in Nukualofa, Tonga. The school educates students aged 11 to 18 .-History:...

, Ngongo attended the University of the South Pacific

University of the South Pacific

The University of the South Pacific is a public university with a number of locations spread throughout a dozen countries in Oceania. It is an international centre for teaching and research on Pacific culture and environment. USP's academic programmes are recognised worldwide, attracting students...

 in Suva

Suva

Suva features a tropical rainforest climate under the Koppen climate classification. The city sees a copious amount of precipitation during the course of the year. Suva averages 3,000 mm of precipitation annually with its driest month, July averaging 125 mm of rain per year. In fact,...

, Fiji

Fiji

Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

, where he studied mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 and economics

Economics

Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...

, and later earned his Doctor of Philosophy

Doctor of Philosophy

Doctor of Philosophy, abbreviated as Ph.D., PhD, D.Phil., or DPhil , in English-speaking countries, is a postgraduate academic degree awarded by universities...

 in Economics at the Australian National University

Australian National University

The Australian National University is a teaching and research university located in the Australian capital, Canberra.As of 2009, the ANU employs 3,945 administrative staff who teach approximately 10,000 undergraduates, and 7,500 postgraduate students...

 in Canberra

Canberra

Canberra is the capital city of Australia. With a population of over 345,000, it is Australia's largest inland city and the eighth-largest city overall. The city is located at the northern end of the Australian Capital Territory , south-west of Sydney, and north-east of Melbourne...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

.

From 19921996 Ngongo was the Deputy Director of Central Planning, and from 19961999 he served in Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

 as Assistant Executive Director at the International Monetary Fund

International Monetary Fund

The International Monetary Fund is an organization of 187 countries, working to foster global monetary cooperation, secure financial stability, facilitate international trade, promote high employment and sustainable economic growth, and reduce poverty around the world...

. After returning to Tonga in 2001, he was appointed as the Director of Fiscal and Economic Policies at the Ministry of Finance. In 2002 he became the Project Manager, Reconstruction and Rehabilitation Operation of Cyclone Waka

Cyclone Waka

Severe Tropical Cyclone Waka was one of the most destructive tropical cyclones ever to impact the South Pacific Kingdom of Tonga. Waka originated within the near-equatorial trough in mid-December 2001, although the system remained disorganized for more than a week...

.

From 20022005 Ngongo was General Manager of Leiola Duty Free Shops as well as the President of the Tonga Chamber of Commerce & Industries in Nuku’alofa. His appointment as Tongan High Commissioner to the United Kingdom was announced by the Ministry of Foreign Affairs on 21 November 2005, replacing Viela Tupou in the post.