Plans for the "Mall of the World" were first revealed 18 months ago, helping to trigger a strong rally in Dubai's real estate and stock markets.
Saturday's formal announcement by the emirate's ruler, Sheikh Mohammed bin Rashid al-Maktoum, appeared to indicate that substantial work on the project would now begin.
The statement did not say when construction would be completed, how much it would cost or how it would be financed.
"The project will be built in phases in alignment with the gradual growth of family tourism in Dubai," said Mohammed Abdullah al-Gergawi, chairman of Dubai Holding, which is Sheikh Mohammed's personal investment vehicle and will develop the project.
The latest version of the plan includes construction of 743,000-square-metre mall, connected to a theme park, theatres, medical tourism facilities and 100 hotels and serviced apartment buildings with 20,000 rooms.
The mall itself would in fact be the second largest in the world after the New South China Mall in Dongguan, which officially has 999,000 square metres of lettable space. However, it is still 36% vacant nine years after it opened. The Dubai complex would be able to welcome 180 million visitors annually. Seven kilometres of promenades connecting the facilities would be opened to the air during the winter but covered and air-conditioned during the summer.
Dubai is still recovering from a 2009 debt crisis and the International Monetary Fund has warned that several new real estate projects could lead to another boom-bust cycle.
But officials say they are able to handle the risks, and a strong economy is helping Dubai's government-linked businesses restructure their debt.