BEIJING, March 15 (Xinhua) -- China aims to build 136 new airports by 2025, government sources said on Wednesday.

The facilities could become a world-class airport complex of international and regional transport hubs, according to a plan by the National Development and Reform Commission and the Civil Aviation Administration of China.

China began an airport construction boom in 2008 when the government began spending on infrastructure to offset the global financial crisis.

Service improved remarkably, but current airports are far from adequate and are unevenly located throughout the country.

By the end of 2015, China has 207 civil airports and is expected to have around 260 by 2020.

In 2015, China's airports handled 910 million passengers and are expected to deal with 1.5 billion passengers in 2020 and 2.2 billion in 2025.