China, which already owns the world's longest high-speed rail network by mileage, is now considering to link existing and future high-speed railway lines into a comprehensive network across the country by 2030, according to a central government blueprint on railway development issued on Wednesday.

The National Development and Reform Commission (NDRC), the nation's top economic planning agency, published the country's latest mid- to long-term railway network plan that will guide railway development in China from 2016 to 2030. The previous plan was first published in 2004 and modified in 2008.

According to the latest plan, by 2025, the country will have rail network of 175,000 kilometers, which includes 38,000 kilometers of high-speed railway.

By 2020, China will have a 150,000-kilometer railway network, of which about 30,000 kilometers will be high-speed railways, covering over 80 percent of major cities nationwide, according to the NDRC.

Sun Zhang, a railway expert and professor at Shanghai Tongji University, told the Global Times Wednesday that one of the highlights of the new plan is that it also aims to meet external demand in the future.

"The high-speed railway between Lanzhou in Northwest China's Gansu Province and Urumqi in Northwest China's Xinjiang Uyghur Autonomous Region, for instance, was a subject of debate in the past, as the region is sparsely populated," Sun said.

"Now that the new plan makes clear it will consider linking with countries along "Belt and Road" initiative (B&R initiative), the debate will come to an end," Sun noted. 

The plan said China's rail development will serve the B&R initiative, boosting connectivity with foreign countries bordering Northwest, Northeast and Southwest China.

Formally known as the Silk Road Economic Belt and the 21st Century Maritime Silk Road, the B&R initiative was put forward in 2013.

"Japan, which is surrounded by sea, is also a major country operating high-speed railway, but China can actually link its high-speed rail network with other countries on the Eurasia landmass," Sun said.

By the end of 2015, China operated 121,000 kilometers of railway, of which 19,000 kilometers are high-speed railway, according to the NDRC. About 10,000 kilometers of high-speed railway are under construction, according to China Railway Corp's official website.

Fei Zhirong, an official with the NDRC, said with continued growth in the railway sector, this is the first time that the country is planning to have a complete web of high-speed railway.

The web will be comprised of eight North-South arteries and eight East-West arteries.