Kuala Lumpur, on Thursday night, the king administered the oath of office to Mahathir. He had previously been the prime minister of Malaysia for more than 20 years.
The opposition alliance won a majority of seats in Wednesday’s parliamentary election, beating the governing coalition led by Najib Razak.
Najib conceded defeat at a news conference. He pledged to accept the people’s decision in the election and respect parliamentary democracy.
Najib also expressed his intention to cooperate in a smooth change of government.