Preparations for the 2026 Asian Games in Japan are going "smoothly", its chairman said Wednesday, after reports the governing body told organisers to make significant improvements.

Japanese media said the Olympic Council of Asia is not happy with preparations for the event in Nagoya and the wider Aichi Prefecture area and has accused organisers of not sticking to the host city contract.

Aichi governor Hideaki Omura, who also serves as chairman of the local organising committee, told reporters that preparations were on schedule.

"We are taking this in a calm manner and my understanding is that preparations are progressing smoothly," he said.

Reports said the OCA has demanded improvements in several areas, including accommodation and transport for athletes and teams.

As many as 15,000 athletes could compete at the September 19 to October 4 Games -- even more than the Olympics.

The OCA has reportedly asked organisers to think again about their accommodation plans, which are said to involve housing athletes in container units and on a cruise ship.

"We received opinions on the progress at a coordinating committee in September. We are preparing based on this," an organising committee spokesman told AFP.

The spokesman added that they have discussions with the OCA on "a daily basis".

AFP has approached the OCA for comment.

The previous Asian Games were held in the Chinese city of Hangzhou in 2023, one year later than planned because of the pandemic.