Air China Ltd has indefinitely suspended flights between Beijing and Pyongyang, citing poor demand as North Korea faces growing sanctions from the United States over its nuclear weapons and missile programs.

An official in the company's Beijing-based press office, who only gave his surname as Ding, said Wednesday that flights were suspended because "business was not good." He declined to comment on when flights might resume.

The suspension by China's national flag carrier comes shortly after a visit by a senior Chinese envoy to the city and also coincides with a U.S. decision to put North Korea back on a list of state sponsors of terrorism.