BEIJING -- A Chinese mainland official said that the south to north operation of the M503 air route was "in line with people's common interests" across the Taiwan Strait, aiming to ease traffic congestion amid growing flights over the Yangtze River and the Pearl River Delta areas.

Ma Xiaoguang, spokesperson for the Taiwan Affairs Office of the State Council, made the remarks at a press conference Wednesday.

"The mainland started south to north operation of the M503 flight route from Jan. 4 this year, which involves no Taiwan flight route or destination and will not affect Taiwan flight safety," Ma said.

In March 2015, the mainland started operation of M503 flight route from north to south, which has run smoothly. Most airlines from Hong Kong, Macao, and Southeast Asia fly this route.

"The Taiwan authority should take a correct view of the route and not make an issue of it to interfere with cross-Strait relations," Ma said.

Figures, however, showed that flight from Hong Kong to Pudong of Shanghai was delayed at an average of 103 minutes last year, up 5.1 percent year on year and the average on-schedule rate of the airway was only 46 percent, according to Ma, who added that the south to north M503 flight route would ease traffic pressure.

"The M503 flight route is located close to the mainland in the Taiwan Strait and in the Shanghai Flight Information Region. The establishment and operation of the M503 route is routine work for the mainland's civil aviation authorities," Ma said.