World Expo opens on Sunday with host Japan aiming to bring humanity together, despite global turmoil and tepid public enthusiasm for the six-month event showcasing innovation as well as Hello Kitty in algae form.

A Mars meteorite the size of a sourdough loaf and a beating heart grown from stem cells are among the myriad futuristic attractions crammed into a vast waterfront site in Osaka hosting more than 160 countries, regions and organisations.

Most pavilions -- each more outlandishly designed than the last -- are encircled by the world's largest wooden architectural structure, a towering latticed "Grand Ring" meant as a symbol of unity.

But with conflicts raging and US tariffs threatening economic chaos, that goal may be optimistic.

"Not for sale" states a yellow and blue sign over Ukraine's booth -- echoing defiant comments from leader Volodymyr Zelensky about the war with Russia, which chose not to mount a display at Expo 2025.

Yahel Vilan, head of Israel's equally compact pavilion, which features a stone from........

© International Business Times