Beijing's new airport will greatly ease the burden on the current airport, but civilian and military use must be coordinated to ensure smooth operations, experts have said.

Approval of the airport, to be located in the south of the capital, was announced on Sunday.

"The rapidly increasing number of passengers has forced the airport in Beijing to run at near-full capacity," said Liu Weimin, a professor of Civilian Aviation Management Institute of China. "A second airport is needed to divert passenger flow."

Beijing Capital International Airport has been ranked as the world's second-busiest airport for three consecutive years.

It handled 81.8 million passenger trips last year, a 4.2 percent increase from the previous year, second only to Atlanta's Hartsfield-Jackson International Airport in the United States.

Shanghai's two airports handled more than 78 million passenger trips in 2012.

"The plan for a new airport has been approved by the State Council," Beijing airport spokesman Li Shengbo said on Sunday.

He declined to give further details, such as when construction will start and what the new airport will look like, as "this is still under discussion".

Zhong Ning, a spokeswoman for the Civil Aviation Administration of China, declined to comment on Sunday.

According to CAAC News, a newspaper affiliated with the aviation administration, large-scale construction will commence next year, and the airport is scheduled to open before the end of 2018.

The airport will be located near the border between

Beijing's southern suburban Daxing district and Hebei province.

It will cost at least 70 billion yuan ($11.2 billion) and have six runways for civil use and one for military use, CAAC News reported, quoting Zhu Wenxin, who works in the office in charge of construction.

The airport will be able to handle 70 million passenger trips annually by 2025, Zhu was quoted as saying.

A rail line will be built to connect the airport with the city center, according to a plan approved by the National Development and Reform Commission.

Passengers will be able to reach the airport within 30 minutes from Beijing South Railway Station with trains running on the 37-kilometer line.

Increasing flight numbers have affected punctuality at Beijing airport, according to media reports.

"Flight delays are frequent," said Iryo Tsukada, a 55-year-old Japanese businessman from Tokyo who travels to Beijing frequently.

"Another airport in the city might provide more options for me."

Yang Yanli, a 26-year-old Beijing accountant, said the airport was too crowded.

"Sometimes you have to line up for a while to take an elevator," she said. "Another airport might ease traffic pressure."

The plan to build a second airport in Beijing was proposed as early as 2008, but the plan was not approved by the State Council and the Central Military Commission until the end of last year, CAAC News quoted Zhu as saying.

"The biggest obstacle to approving building the airport is a dispute in distribution of airspace between civil and military use," Zhu said.

The new airport will be built close to Nanyuan Airport, which is mainly for military use, in the southern suburban district of Fengtai.

Some flights handled at Nanyuan Airport will move to the new airport after it is completed, according to Zhu.

Liu Weimin, the professor at the Civil Aviation Management Institute of China, said civil and military use must be coordinated for smooth operations.

The military usually has airspace priority, Li said.

"The current law on civil aviation was made in 1995, and it should be revised after 18 years of tremendous changes in society and rapid economic development," he said.

Liu suggests more rights be given to civil aviation so it can play a bigger role.

"Besides, the new airport and the current one should have a clear division of duty to better serve the customers," he said.

Zheng Xin contributed to this story.