TOKYO (Kyodo) -- The number of visitors to the World Exposition in Osaka topped 1 million on Friday, the 13th day of the event, organizers said.

A total of some 1.02 million people visited ahead of Japan's Golden Week holiday period which started Saturday. Organizers have targeted attracting over 28 million visitors for the six-month event through Oct. 13 on Yumeshima, an artificial island in Osaka Bay.

The event saw its busiest day on April 13 when 124,000 people entered the venue, but the number has remained below 100,000 since.

A daily average of some 150,000 visitors is needed to achieve the goal of 28 million, according to organizers, demonstrating the need for more promotional efforts to increase numbers.

On Wednesday, organizers held a ceremony to mark 1 million visitors to the expo, based on a tally that included workers and media members.

When Japan last hosted the expo in Aichi Prefecture in 2005, it took 17 days from the opening for the number of visitors to hit 1 million.