Governor Lt Gen (Retd) Nirbhay Sharma administered the oath of office to Chawngthu at a function at Raj Bhavan.
Chief Secretary Lalmalsawma told PTI that portfolios of Chawngthu and K S Thanga were likely to be alloted on Monday next.
Thanga was administered the oath on Wednesday.
Chawngkunga, president of the Mizoram Pradesh Youth Congress Committee, was elected from Hrangturzo seat in central Serchhip district in a bye-election.
Thanga and Chawngthu were inducted in the council of ministers following the resignation of Labour Minister Lalrinmawia Ralte and Fisheries Minister Buddha Dhan Chakma.
Disclaimer: No Business Standard Journalist was involved in creation of this content