China’s airlines face a growing need to expand their operations beyond the domestic market as competition from a more reliable and efficient rail system stiffens. Still, trend lines showed slowing growth of international traffic among Chinese airlines last year, due largely to geopolitical influences such as South Korea’s decision to install a U.S. antimissile system in its territory.

China’s 12,500-mile high-speed rail (HSR) program now forms 60 percent of the world’s existing HSR. The Beijing-to-Shanghai train alone carried 460,000 passengers last September, and 1.47 billion passengers traveled on trains in 2016. It will further strengthen its place in China’s domestic transport system as the country institutes plans to double the network by 2035.

According to the Civil Aviation Administration of China (CAAC), domestic flights still grew humbly, from 10 percent in 2016 to around 13 percent for the first 11 months of 2107. But, thanks largely to the proliferation of the country’s rail system, Chinese carriers increasingly have turned their sights to international markets.

Speaking at a panel at the Aviation Festival Conference held in Singapore, China West Air marketing and sales general manager Yang Haijun highlighted a growing widebody fleet within China, as more carriers seek to boost their international networks in sync with relaxed flying rights to the UK, France, and the U.S. For example, the UK inked an agreement with China in 2016, increasing weekly flights from China to 200 from 80.

Also appearing at the conference, China Southern Airlines marketing director Shen Zeyou noted that stiffer competition from more players has driven the cost of international flights down, thereby attracting more outbound travelers.

However, growth in international traffic slowed significantly last year, as China saw a reversal of a trend begun in 2011, when international travel volumes surpassed those of domestic travel for the first time. China’s CAAC reported 6 percent growth in international traffic for the first 11 months in 2017, compared with 33.3 percent in 2015.

Shen added that his airline instituted several new routes in 2016, such as Guangzhou to Adelaide and Toronto; however, plans for this year calls for China Southern to turn its attention to increasing frequencies instead. The airline plans to take delivery of 105 new aircraft this year, including examples of the Airbus A330-300 and Boeing 787-9.

Meanwhile, West Air’s Yang expressed wariness of expanding internationally, despite earlier aspirations to venture beyond the airline’s sole international destination of Singapore. He said that West Air will instead rely more heavily on interline passengers from parent HNA Group through the western regions. He also told AIN that despite the common belief that the One Belt One Road initiative would open new markets for West Air, the Central Asia market hasn’t matured enough to pique his interest, while the nearest Central Asia city lies more than seven hours from West Air’s hub in Chongqing, too far away for its Airbus A320-family fleet.