Major Chinese airlines operating flights between China and the United States have pushed back against a US proposal to bar them from flying over Russian airspace for round-trips to and from the US. The ban, if finalized, could take effect from as early as November.

Last week, the US proposed the ban through an order claiming that Chinese carriers gain an unfair cost advantage over their US counterparts on such flights, as US airlines are prohibited by Moscow from using Russian airspace.

In a filing to the US Department of Transportation on Tuesday, seven Chinese airlines requested an extension to seven business days to respond to the order. The US order had initially set an unusually short comment period of just two business days.

Industry experts said that if implemented, the ban would undoubtedly harm the public's interests. It will disrupt travel for a large number of passengers, drive up airfares and force some travelers to switch to connecting flights via Hong Kong, Japan or South Korea.

Qi Qi, a senior independent civil aviation industry analyst, described the US demand as highly unreasonable and unprofessional, given that rerouting flights requires considerable time for assessment.

"In contrast, the response of the Chinese airlines has been professional and based on scientific considerations. It is hoped that the US will approach this matter with greater rationality and align its considerations with practical feasibility," Qi said. "Compared to the pre-pandemic period, both demand and supply for China-US flights have declined, with supply dropping at a higher rate. As a result, supply still falls short of demand, which is driven by business travel and exchanges between the two countries."

The US move came at a time when tensions in China-US trade and economic relations have been escalating in recent weeks.

The seven Chinese carriers that filed documents are Air China, China Eastern Airlines, China Southern Airlines, Hainan Airlines, Sichuan Airlines, Xiamen Airlines and Capital Airlines. Of these, Capital Airlines is currently not operating flights between China and the US.

Air China said that it is assessing the impact of the proposed restriction. It has requested an extension of the comment period to seven business days to complete its assessment and prepare a meaningful response to the order.

Lin Jian, spokesman for the Chinese Foreign Ministry, said at a regular news briefing on Wednesday that the restrictions imposed by the US targeting Chinese airlines were not conducive to people-to-people exchanges between the two countries and will harm the interests of the US itself.

Lin said that the proposed restriction has been met with strong opposition in the US itself, and the ministry supports Chinese enterprises in safeguarding their legitimate and lawful rights and interests.

As of September, there were 21 direct China-US routes in operation, served by nine airlines, including six Chinese carriers and three US carriers: United Airlines, American Airlines and Delta Air Lines. Chinese airlines accounted for 50.73 percent of the actual operated services, while US airlines made up the remaining 49.27 percent, according to Flight Master, a travel services platform.

"If China-US flights were rerouted, travel time would increase by several hours and airfares would rise further. This will undoubtedly take a significant toll on business and trade exchanges between the two countries," said Lin Zhijie, an independent civil aviation industry analyst. "The US government has been resorting to various unreasonable demands, as it intends to disrupt exchanges between the two countries and hinder interactions between the two peoples. If China-US flights are suspended, it would ultimately harm the interests of the public on both sides."

He further noted that currently, only US airlines are authorized to operate US-China routes with a stopover in Tokyo, the capital of Japan. In this regard, he suggested that in line with the principle of reciprocity, Chinese airlines should also be allowed to operate similar stopover routes between the two countries via Tokyo.