In a clandestine operation that marks a ramping up of American actions against economic espionage ordered by Beijing, FBI agents lured a Chinese spy to Belgium before spiriting him to the U.S.

Yanjun Xu, a senior officer with the Ministry of State Security, or MSS, now faces up to 25 years in jail. He was arrested in Belgium six months ago and charged with conspiring and attempting to commit economic espionage by stealing trade secrets from multiple U.S. aviation and aerospace companies, including GE Aviation.

Bill Priestap, head of the FBI's counterintelligence division, described the extradition of a Chinese intelligence officer as "unprecedented." It is unclear whether other U.S. intelligence agencies, like the CIA, were involved.

Xu, also known as Qu Hui and Zhang Hui, was extradited to the U.S. on Tuesday and appeared in federal court in Cincinnati on Wednesday. Belgian authorities provided “significant assistance” in securing Xu’s arrest on April 1, according to the Justice Department.

Court documents unsealed Wednesday say that China’s intellectual property polices focus on the “re-innovation” of foreign technology, often obtained through “theft.” China’s MSS is its civilian spy agency, responsible for counterintelligence, foreign intelligence, and domestic political security.

"This case is not an isolated incident," said John Demers, head of the Justice Department's National Security Division, in a statement. "It is part of an overall economic policy of developing China at American expense. We cannot tolerate a nation's stealing our firepower and the fruits of our brainpower."

Xu began his espionage efforts around December 2013, and his activities continued until his arrest, said the Justice Department. One of those companies he targeted was GE Aviation, which is based in Cincinnati.

According to the indictment, Xu identified experts in the aviation field and recruited them to travel to China, often under the impression they would deliver a university presentation. He would get the experts to go by passing himself off as an official with the Jiangsu Science and Technology Association.

Xu and other Chinese operatives discussed in messages how they would obtain “highly sensitive information” from the aviation experts. Then, Xu would exchange information with individuals at Nanjing University of Aeronautics and Astronomics, which is operated by the Chinese government.

NUAA is considered a top engineering university in China, and it has significant influence over China’s aerospace industry, according to court documents. Xu faces a maximum of 25 years in prison if found guilty of all charges.

The indictment comes just days after Secretary of State Mike Pompeo traded public barbs with China’s top diplomat, Chinese Foreign Minister Wang Yi, during his diplomatic tour of the region.

“U.S. actions have damaged China’s rights and interests, undermined China-U.S. mutual trust and cast a shadow over China-U.S. relations,” Wang said, per a readout from the Chinese Foreign Ministry. “We urge the U.S. to immediately stop its misguided comments and actions.”

The remarks come after Vice President Mike Pence criticized China in a wide-ranging speech last week in which he charged Beijing with pressuring Taiwan, abusing human rights within the country and militarizing the South China Sea.

“The issues that you’ve characterized we have a fundamental disagreement,” Pompeo told Wang on Monday. “We have grave concerns about the actions that China has taken, and I look forward to having the opportunity to discuss each of those today because this is an incredibly important relationship.”

Last month, federal officials alleged that an electrical engineer working on behalf of Chinese intelligence officials enlisted in the U.S. Army Reserves and sought to target other potential defense industry sources.

Demers said: “No one begrudges a nation that generates the most innovative ideas and from them develops the best technology. But we cannot tolerate a nation stealing our firepower and the fruits of our brainpower. We will not tolerate a nation that reaps what it does not sow.”