At exactly 20:20 local time, the skyscraper was lit up with “1 year to go" and “the world's greatest show" in both English and Arabic.

“These spectacular nationwide celebrations will usher in the final leg of a historic journey," said Reem Al-Hashimy, a government minister and also director general of Expo 2020.

“The next 12 months will see us put the finishing touches to ensure an exceptional World Expo."

Dubai hopes to attract 15 million visitors to the sprawling site taking shape on sand dunes south of the city's gleaming downtown, being built at the staggering cost of 30 billion dirhams (8.2 billion dollars).

With the city in the grips of a downturn in its vital property sector, officials are pinning high hopes on the event, the logo of which is emblazed on everything from business cards to airliners.

Some 200 countries will take part in the fair, which runs from October 20, 2020, to April 10, 2021.

Attractions will include the UAE pavilion in the shape of a falcon in flight and a dome crafted from 800 tonnes of steel which will be the world's largest 360-degree projection surface.

Organisers say the Expo is much more than a six-month trade show.

But although experts believe the much-anticipated event will give the economy a boost, there are concerns it will be only a temporary one and that finances will slump again as soon as the show is over.

Economic hangover 

Since the first “World Expo" was held at the Crystal Palace in London in 1851, world fairs have been used to showcase new ideas and technology as well as serving as nation-branding exercises.

But not all have had the desired impact, with some marred by disappointing visitor figures and leaving a legacy of debt and abandoned infrastructure.

Raed Safadi, chief advisor to Dubai Economy which is charged with guiding the emirate's financial fortunes, said Expo will add some $34.6 billion to the economy between 2013 — when it won the bid to host the event — and 2030.

“It will be gross value added, directly, indirectly and induced. You come to Expo, you stay at a hotel, you go shopping, etc.," he told AFP.

“As preparations for the Expo come to an end, activity in the construction sector is likely to weaken," it said.

Already there are concerns of huge oversupply in the property sector, driven by predictions that the trade fair will deliver some 300,000 new jobs which saw hundreds of major projects unveiled in recent years.

Also in the spotlight is the government's goal of attracting 20 million tourists in 2020, an increase of around 20 percent from this year.

The all-important arrivals figure has been stagnant at 16 million in recent years, and there are doubts that Expo will singlehandedly bridge that gap.

Standard and Poor's ratings agency said in September that it expected Dubai's economy to pick up with 2.4 percent growth this year, from 1.9 percent in 2018, largely due to the completion of projects related to the Expo.

But after the event packs up, growth will drop to a modest 2.0 percent through 2022, it said.

-AFP