Image copyright Getty Images Image caption China's new mega-airport is the size of 98 football fields

China's new $11bn (£8.8bn) mega airport has opened its doors, days before the country's 70th anniversary celebrations.

The Daxing International Airport in the capital Beijing was formally opened by President Xi Jinping on Wednesday.

The airport spans 700,000 square metres, or 98 football fields, says state media outlet China Daily.

Beijing's existing airport is the world's second busiest behind Atlanta, according to the Airport Council.

But officials say a new airport was needed to take the pressure off the overcrowded Beijing Capital International Airport.

Media playback is unsupported on your device Media caption What does the world's largest single-building airport terminal look like?

The Daxing airport - said to be the world's largest terminal in a single building - is expected to receive a large amount of the 170m passengers the city expects to welcome by 2025.

According to state agency the Global Times, seven domestic airlines were expected to begin operations out of the new airport on Wednesday. The first flight - a China Southern Airlines A380 - took off at 16:23 local time.

And international carriers including British Airways, Cathay Pacific and Finnair have already announced routes to Daxing.

The new airport, which is located around 46km (29 mi) south of Tiananmen Square, was designed by famed architect Zaha Hadid.

With the opening of the airport, Beijing has joined a group of cities, including New York and London, that have two-long haul international airports.

More than 100 million passengers have used Beijing Capital, which opened in 1958.

Image copyright AFP Image caption Daxing Aiport in June 2019