"While our service between the United States and HKG (Hong Kong) remains an important part of our network, we have decided to discontinue service between ORD (Chicago) and HKG following the return from HKG on September 9, 2019," said the company in a statement.
The majority of protests have been peaceful, but groups of protesters closed the city's international airport two days earlier this month.
United also plans to stop the service between Guam International Airport (GUM) and Hong Kong starting October 14, a change previously announced.
At the same time, United Airlines confirmed to CNN that it will add a second flight between San Francisco and Hong Kong this fall to complement its existing service. "We look forward to our upcoming addition," the company added.