Mr Aingimea was elected in parliament after former president Baron Waqa lost his seat in Saturday's general election.
He named his cabinet Wednesday.
Mr Aingimea is Minister of Foreign Affairs and will hold a series of more minor portfolios.
All six of the other cabinet posts are filled by newly elected MPs.
They include Martin Hunt in Finance, Isabella Dageago as Health Minister and Maverick Eoe becomes Minister of Justice.
During the swearing in Mr Aingimea said "we have just witnessed the swearing in of your government - a government reflective of the wishes of the people. As I articulated in my adjournment debate in parliament yesterday, this government's foremost duty is to unify the nation."
The President then used the Biblical quote, "if a house is divided against itself it cannot stand."
President Aingimea’s portfolio includes Chairman of the Cabinet
Minister for Public Service; Foreign Affairs & Trade; Nauru Police Force; National Emergency Services; Telecommunications and Media; Multicultural Affairs; Education; Land Management; Nauru Air Corporation; Port Authority of Nauru; Eigigu Solution Corporation; Nauru Phosphate Royalties Trust; Naoero Postal Services Corporation; Nauru Tourism Corporation; Cenpac Corporation; Nauru RPC Corporation; Eigigu Holdings Corporations Transport Services; and Nauru Sports Development Inc.
Hon. Martin Hunt, MP:
Minister Assisting the President; Finance & Sustainable Development; Transport; and Eigigu Holdings Corporation.
Hon. Isabella Dageago, MP:
Minister for Health; and Home Affairs.
Hon. Rennier Gadabu, MP:
Minister for Commerce, Industry & Environment; Climate Change; and Infrastructure Development.
Hon. Maverick Eoe, MP:
Minister for Justice & Border Control; and Sports.
Hon. Reagan Aliklik, MP:
Minister for RONPHOS; and Nauru Rehabilitation Corporation
Hon. Wawani Dowiyogo, MP:
Minister for Fisheries; and Nauru Utilities Corporation.