A Japanese balloonist has unveiled what he calls one of the world's largest hot-air balloons ahead of his attempt next month to become the first Japanese to complete a trans-Pacific flight.

Michio Kanda, 53, a world-record holder in flight duration and distance records in several categories of hot-air ballooning, weighed his colorful creation -- 36 meters high and 26 meters in diameter -- at a riverbed in Tochigi Prefecture over the weekend.

The Milky Way 2 is the second biggest balloon in the world but the largest one made by hand, Kanda claimed.

Kanda, who works at the municipal board of education in Kawajima, Saitama Prefecture, said he also designed the balloon's skin in two layers to improve heat insulation and halve fuel consumption.

He said he and his partner, Masashi Kakuta, 40, plan to attempt the trans-Pacific flight sometime next month from Tochigi Prefecture.

But he said that the situation surrounding Iraq has prevented them from finalizing their schedule.

"It's highly likely we'll cross the Pacific successfully. I'm confident," said Kanda, who is also a holder of the Naomi Uemura Prize, which commemorates the late Japanese adventurer who was first in the world to climb the highest peaks on five continents.