Tokyo’s highest official is casting doubt on government plans to institute daylight saving time in 2019 and 2020 to help manage the scorching heat during the Summer Olympics.

Tokyo Gov. Yuriko Koike said Monday that she was concerned about the expense and disruption of moving clocks forward by two hours during summer months for two years only. Koike said that she also has heard worries expressed about the difficulty of introducing the measure in time for the Tokyo Games.

"A lot of people are concerned about the cost and social instability caused by having it for just two years," she said in an interview at her office, adding that she wasn't opposed to a more permanent move. "Separately from the Olympics and Paralympics, I think it is worth considering."