It is reported by Sky News channel.
It is noted that the party won 27 seats, followed by the Democratic Unionist Party (DUP), which has 24 seats.
The DUP has already said it may boycott the government.
In October, it became known about the intention of representatives of the UK and the EU to hold consultations on changing the points of the protocol on Northern Ireland, signed as part of the Brexit agreement.
Under the provisions of the Northern Ireland Protocol, Northern Ireland remained a customs area of the EU.