Northern Ireland lawmakers have appointed Arlene Foster as the first female leader of their unity government.

The 45-year-old Foster has risen swiftly in the Democratic Unionist Party, which represents the British Protestant majority.

She was elected unopposed last month to succeed Peter Robinson as party leader following his November resignation announcement.

On Monday, Northern Ireland Assembly lawmakers appointed her unopposed to succeed Robinson also as leader of the 9-year-old government.

Foster pledged to improve relations with Irish nationalists on the other side of the chamber. She said Catholic and Protestant voters alike were sick of their seemingly endless arguments.

Foster said: "I will do all I can to change the political culture of this place, but I can't change that alone. We can only do it by working together."