China's northwest regions are planning to invest more in air transportation in coming years, aiming to unlock the potential of Silk Road tourism through better connectivity.

Shaanxi province, whose capital, Xi'an, was the starting point of the ancient Silk Road, will increase flights with nations involved in China's Belt and Road Initiative.

The initiative refers to the Silk Road Economic Belt, which will link China with Europe, and the 21st Century Maritime Silk Road, a sea route stretching from southern China to Southeast Asia and Africa. The added Silk Road in the air is also expected to contribute to tourism development.

Qin Zhanxin, vice-president of China West Airport Group, said that in the next five years, Xi'an Xianyang International Airport will add routes connecting Xi'an with Central, Western and Southeast Asia regions and expand airlines to Europe, the United States and Australia.

"By the end of 2020, the airport will handle 50 million passengers and 5 million international passengers, and become the 40th-busiest airport in the world," Qin said.

Gansu province, with more than 1,600 kilometers of the Silk Road, is planning to invest 46.2 billion yuan ($7 billion) over the next six years to complete 24 key aviation projects connecting the major cities along the Silk Road Economic Belt.

"Taking full advantage of the air routes and huge number of passengers will help to build international tourism destinations along the Silk Road," said Yang Jun, deputy head of the Xianyang tourism authority.

Li Jinzao, director of the China National Tourism Administration, said transportation and other issues regarding visa policies, marketing and security have kept the Silk Road tourism market from reaching its full potential.

"Not even one-fifth of outbound Chinese tourists visited the Silk Road," Li said.