Kong Qingxin, director-general of the ministry's promotion center for emergency assistance, said rescue response time will be possible within 15 minutes in major cities.

About 1 million square kilometers - 11 percent of country's land area - will be covered.

"Two-thirds of those seriously injured in incidents or natural disasters will die within 25 minutes. With immediate medical treatment within 15 minutes, 80 percent of those injured will survive," said Chen Ping, deputy director-general of the promotion center.

In the next 10 to 15 years, at least 30 billion yuan ($4.7 billion) is needed to establish 850 rescue bases with 1,050 helicopters, Kong said at a helicopter forum in Tianjin on Wednesday, ahead of the First China Helicopter Exposition.

The exposition runs from Thursday to Sunday.

According to Kong, there will be nearly 300 sites for about 350 helicopters along major freeways in the east by the end of 2020. An additional 260 bases and 300 helicopters will cover 50 highly populated large- and medium-size cities.

Hundreds of additional helicopters are needed to resolve rescue problems in sparsely populated and remote areas.

Ministry of Transport flight teams currently have 11 rescue bases, 12 helicopters and eight rented aircraft.

Since it was launched in 2001, the team has implemented more than 1,500 rescues in extreme weather and sea conditions, saving nearly 2,000 lives, said Zhang Jinshan, deputy director of the rescue and salvage bureau of the Ministry of Transport.

Across the nation, only 294 helicopters are available for rescue operations, an average of three per 100,000 square kilometers on average, far less than developed countries, Chen said.

According to international standards, each helicopter rescue base should cover a radius of 50 km, said Chen.

"With reductions of government constraints on low-altitude airspace, helicopters will be irreplaceable in saving people's lives," Chen said.

The nation's first exclusive aviation rescue training base is gearing up for construction in Guangdong province, Chen said.

Yin Zhigang, deputy general manager of China Flying Dragon General Aviation, expressed his concerns about the present condition of helicopter medical aid in China.

"Several hospitals in Shanghai, Chongqing, Nanjing and Tianjin have established buildings with landing pads. However, due to the quantity and cost of helicopters, helicopter medical aid still remains at the test stage or only for occasional use. Basically, helicopter medical aid is still a blank in our country".