China is building a pan-Asian high-speed railway to link the nation with Myanmar, Vietnam, Cambodia, Thailand, Malaysia and Singapore, a railway expert told the Global Times on Thursday.

Domestic construction has already started on some high-speed rail lines linking China not just to Asia but also to Europe and even the US if cross-border deals can be agreed, said Wang Mengshu, a member of the Chinese Academy of Engineering.

Domestic construction on the pan-Asian railway kicks off in June starting in the southwestern Chinese city of Kunming, capital of Yunnan Province, and the track to Myanmar will become a convenient passage leading China to South Asian countries, Wang said.

Construction includes a 30-kilometer tunnel through the border mountains of west Yunnan Province and east Myanmar, and would take about four years, Wang said.

"International negotiations and cooperation would be the key issues to push forward those projects," Wang said.

China will provide funds, technology and equipment in exchange for natural resources from countries down the line. Negotiations are already underway, he said.

"The 'going abroad' strategy involves juggling trade, finance and energy concerns and requires efforts from governments on all sides," Li Hongchang, a railway expert and economics professor at Beijing Jiaotong University, was quoted as saying by the Xinhua News Agency.

China could lose out from the ambitious railway plan, said Zhao Jian, a professor at Beijing Jiaotong University.

"It will take decades for those countries to pay back and China also has to take the risk that those governments may change their minds and abolish the agreements," Zhao said.

The demand for high-speed rail in foreign countries is not strong enough, he believed.

China has the world's longest high-speed railway network of 11,028 kilometers, with another 12,000 under construction.

Chinese Premier Li Keqiang has been deploying "high-speed railway diplomacy" during overseas trips since he took office in March 2013.

In Addis Ababa on Monday, the first stop in a four-nation tour of what he called the "continent of hope," Li outlined a plan to connect all major African cities through a high-speed railway network.

Li pledged "no strings" support for an African plan to develop a continent-wide high-speed rail network and said China has set aside $2 billion for a China-Africa Development Fund.

During Li's state visit to Thailand in October 2013, the two countries signed a memorandum of understanding in which China said it would seek to participate in a high-speed railroad project in Thailand in exchange for agricultural products.

Wang said a 13,000-kilometer high-speed rail line from northeastern China to Canada and the US is also being considered. The plan is to go through Siberia to the Bering Strait and then tunnel across to Alaska.

Such a project would enable Chinese people to reach the US within two days.