BEIJING, Jan. 22 (Xinhua) -- A Chinese official said Monday that progress has been made in expanding the China-Europe express freight train service.

A total of 3,673 trips were made last year, more than double that of 2016 and exceeding the total launched during the past six years, Yan Pengcheng, spokesperson at the National Development and Reform Commission, told a press conference.

Initiated in March 2011, the service has expanded rapidly and is expected to rise to 5,000 trips in 2020. Faster than sea and cheaper than air, China now has express freight service to 36 European cities.

Beside the expanding network, efforts have been made to lift efficiency while lowering costs. Yan said travel time had been shortened to less than two weeks from more than 20 days for many journeys, and transport costs have been cut 40 percent.

"China will continue to cooperate with relevant countries in 2018 to improve the quality and efficiency of the China-Europe freight train service and build it into a competitive international logistics brand," he said.

The European Union remained China's largest trade partner in 2017, with the volume of bilateral trade surging 15.5 percent from a year earlier.