TOKYO: Tokyo governor Yuriko Koike declared victory in Sunday's vote to elect the leader of one of the world's most populous cities and immediately vowed to step up the fight against a recent coronavirus resurgence.

Major media exit polls suggested a landslide victory after voting stations closed at 8:00 pm (1100 GMT), as Koike shrugged off challenges from a wide range of candidates, many of whom were political novices.

The 67-year-old media-savvy Koike is a rare top female leader in Japan's male-dominated politics and is often mentioned as a possible prime minister.

Many observers say her smooth performance during the coronavirus pandemic contrasted sharply with current PM Shinzo Abe, who critics say bungled Japan's response.

The postponed Olympics, due to open on July 23, 2021, were also a major theme of the campaign and Koike pledged to reduce the Games budget as organisers grapple with the unprecedented challenge of rescheduling the event.

Koike gave an "online" victory speech in front of a limited number of journalists to minimise the risk of coronavirus infection.