BEIJING, Feb. 28 (Xinhua) -- The investigation conducted by the United States into a stray Chinese civilian unmanned airship lacks credibility and objectivity, only serving the political interest of the U.S. side to smear China, an expert on China-U.S. relations told Xinhua.

Wang Wen, executive director of China-U.S. People-to-People Exchange Research Center at Renmin University of China, said there is no specific international law that can be used as a reference for the airship that drifted into the United States due to force majeure earlier this month, so relevant countries should follow international practices.

According to international practices, if an airship or a balloon of one country enters the airspace of another country accidentally, the latter should first determine whether it belongs to the former. Then, the latter should maintain communication with the former over the incident in a restrained and sincere manner and escort the airship to make sure it is under control. Finally, the latter could force it to land if the airship is off course, Wang said.

It is very irrational and improper to shoot down the Chinese civilian airship with missiles, he said, adding that there are rational Americans who think the U.S. government, especially the military, is overreacting.

"Washington doesn't need to make such a fuss," Wang said, noting this as an example of how abusing the use of force has long been ingrained in the United States.

Wang noted an article by Pulitzer Prize-winning American journalist Seymour Hersh, who disclosed that the United States was behind the explosions of the Nord Stream pipelines. Wang also mentioned that a disastrous train derailment in the U.S. state of Ohio resulted in significant air and soil contamination.

"Such events are affecting the approval rating of the Biden administration," said Wang.

The United States intends to further stigmatize and demonize China through the airship incident, hyping up the "China threat" narrative, so as to deflect domestic and international accusations, Wang said, calling out the investigation for being based on the "presumption of guilt."

The United States has framed the airship as a "spy balloon," which is "a thief crying 'stop thief'," Wang said.

Calling the United States the number one country in surveillance, Wang said that Washington has been spying on many world leaders, even the leaders of its European allies. "This has been revealed by former National Security Agency contractor Edward Snowden and the founder of Wikileaks Julian Assange."

"Is the United States showing off its strength and bravery, or is it showing that it is fragile and not confident in its national security? In the eyes of the Chinese, this exposed the hegemony of the U.S. government and its violation of international law," Wang said.