Western Australia Premier Mark McGowan resigned on Monday in a surprise announcement, citing exhaustion.
McGowan, elected premier in 2017, is a member of Australia's ruling Labor Party, which also holds a large majority in Western Australia. He will also step down from the state parliament this week, he told a news conference.
"I have loved the challenge of solving problems, making decisions, getting outcomes, and helping people. But the truth is I'm tired, extremely tired. In fact, I'm exhausted," McGowan said.
The state is the country's largest by area and is rich in resources including iron ore and natural gas.
(Reporting by Alasdair Pal in Sydney; Editing by Lincoln Feast)
