Zelenskiy will take part in a session regarding peace and security alongside the G7 leaders and invited outreach countries, according to the foreign ministry.
The Ukrainian president is set to arrive in Hiroshima on Saturday, and is expected to hold bilateral meetings with other attendees of the G7 summit.
White House national security adviser Jake Sullivan said on Saturday that the United States is not flying Zelenskiy to Japan, but adding that it was a "safe bet" that U.S. President Joe Biden would meet the Ukrainian leader there.
Sullivan told reporters that Biden on Friday endorsed training the Ukrainian military to fly F-16 fighter jets and other aircraft, adding that weapons assistance to Ukraine was changing as the conflict changed.
"As the training unfolds in the coming months, we will work with our allies to determine when planes will be delivered, who will be delivering them, and how many," Sullivan said.