The first world fair to be held in the Middle East, Expo 2020 Dubai, has opened with a lavish ceremony of fireworks, music and messaging about the power of global collaboration for a more sustainable future.
Stars headlining the opening ceremony, which was projected in public spaces around the UAE, included Italian tenor singer Andrea Bocelli, British singer Ellie Goulding, Chinese pianist Lang Lang and Saudi singer Mohammed Abdu.
Dubai - the region's tourism, trade and business hub - is hoping to boost its economy by attracting 25 million business and tourist visits to the world fair which has been built from scratch on 4.3 sq km of desert.
Many countries and companies are also looking to the expo - the first major global event open to visitors since the coronavirus pandemic - to boost trade and investment.
The full expo site will open its doors to exhibitors from almost 200 countries on Friday after being delayed for a year by the pandemic.
Chosen eight years ago to follow the 2015 Expo in Milan, Italy, the event cost about $US6.8 billion ($A9.4 billion).
Dubai says it wants the Expo, an exhibition of culture, technology and architecture under the banner "Connecting Minds and Creating the Future," to be a demonstration of ingenuity and a place where global challenges such as climate change, conflict and economic growth can be addressed together.
The event will probably contend with a global reluctance to travel and many events will be streamed live online.
But Expo still officially expects to attract more visits than Milan received and more than twice the population of the UAE.
"We are quite confident... that by being responsible in how we manage the situation with COVID but also in how we put forward an exciting program for visitors, we will hopefully be able to thread the needle by opening up but remaining at the same time conservative and keep public safety first and foremost," Reem Al Hashimy, Expo 2020 Dubai's Director General told Reuters.
The Gulf state has relaxed most coronavirus restrictions but Expo requires face masks to be worn and for visitors over 18 to be vaccinated against, or test negative for, COVID-19.
Before the pandemic, the consultancy EY forecast that the Expo would over the course of its six months contribute 1.5 per cent of the UAE's gross domestic product.
Australian Associated Press