From 2003 to 2006 he served as Chairman of the Alliance of Small Island States, and from 2006 to 2011 as Ambassador/Head of Bilateral Directorate for Asia and the Middle East.
[1] In 2016, Koonjul was awarded Grand Officer of the Order of the Star and Key of the Indian Ocean (G.O.S.K) and later in 2022, the Grand Commander of the Order of the Star and Key of the Indian Ocean (G.C.S.K) for "valuable contribution in the field of diplomacy, particularly, for the effective completion of the decolonisation process of Mauritius.
"[5][6] In February 2022, Koonjul as Permanent Representative of Mauritius to the United Nations led a fifteen day Mauritian expedition to the islands of the Chagos Archipelago, which recent decisions by the International Court of Justice, United Nations General Assembly and the International Tribunal for the Law of the Sea had supported Mauritius' claim to the islands, rather than the United Kingdom's British Indian Ocean Territory claim.
Prime Minister of Mauritius, Pravind Jugnauth, said this was not to embarrass the UK, but "merely an exercise of our sovereignty over part of our territory and that is in accordance with international law.
[8][9] The main purpose of the expedition was to survey the unclaimed Blenheim Reef, to discover if it is exposed at high tide so is claimable.