CHONGQING, Dec. 26 (Xinhua) -- Freight trains made a total of 6,235 trips on 57 routes since the China-Europe freight train services began in 2011.

The cross-border rail network has bridged 35 Chinese cities with 34 European cities in 12 countries over the past six years.

In 2017, more than 3,270 journeys have been made between cities in the two continents, according to the transport coordinating committee of China-Europe trains Tuesday.

The number of such train trips is expected to reach 4,000 in 2018, according to Zhao Jun, head of the freight department of China Railway Corporation.

"We will focus on raising the efficiency and profits and lowering the empty-loading ratio next year," Zhao said.

The China-Europe rail service is considered a significant part of the Belt and Road Initiative. It is expected to boost trade between China and Europe, China's largest trading partner.

In the first 10 months, trade between the two sides increased 16.2 percent year-on-year to 3.4 trillion yuan (513 billion U.S. dollars).