The respective governments of China and Russia are seriously considering the idea of building a high-speed railway line between their two capital cities, according to reports.

The Beijing Times said that the line, which would be over 7,000 kilometres but cutting the Trans-Siberian railway journey from six days to two, would cost in excess of $230bn (£142.9bn, €179.5bn) if it is to connect Moscow and Beijing via a high-speed railway line.

If it were to be completed, it would be triple the length of the world's longest high-speed line which runs from Beijing to Guangzhou.

Wang Meng-shu, a tunnel and railway expert at the Chinese Academy of Engineering, told the Beijing Times: "If the funds are raised smoothly... the line can be completed in five years at the quickest."

Vladmir Putin and Premier Li Keqiang signed a memorandum of understanding when China's head of government travelled to Moscow earlier in the week, with the duo outlining their interested in building a high-speed link between Moscow and Kazan in the Tatarstan region, an area which holds vast amount of oil, China Central Television (CCTV) reported.

It was reported earlier in the year that China was considering building a 13,000km high-speed railway line that would run from Beijing to east coast US.

The line, creatively dubbed the China-Russia-Canada-America line, would begin in Beijing, travel north through Siberia, and under the Bering Strait to Alaska before heading south through Canada to reach its final - unspecified - destination in the United States.