The Imperial Household Agency on Saturday introduced a same-day registration system for guided tours of parts of the Imperial Palace in central Tokyo so some visitors can gain entry without prior reservations.

The measure was taken in line with the government's strategy to boost tourism as the nation aims to increase the annual number of overseas visitors to 40 million by 2020, when Tokyo hosts the Olympic and Paralympic Games.

Explanations and instructions by staff are currently given in Japanese only during the 75-minute tour. The agency said it is trying to prepare voice guidance in other languages.

Under the new arrangements, the maximum number of visitors will be increased to 500 from 300 for each of the tours, with same-day registration available for 300 people, the agency said.

The tours will be conducted twice a day, from Tuesday to Saturday, but will not be available on Sundays and Mondays.

The points visitors can view during the tours include the East Gardens, the Seimon Tetsubashi Bridge and the Imperial Household Agency building.

Visitors who want to register the same day should finish their registration procedures before the morning and afternoon tours begin, at 10 a.m. and 1:30 p.m. respectively, by showing identification and filling an application form, the agency said.

The place for the registration is outside the Kikyomon Gate of the Imperial Palace near Tokyo Station.