China slammed the recent launch of a full-fledged U.S. investigation into China's alleged international property theft on Monday, calling the probe "irresponsible."

"The United States' disregard of World Trade Organization rules and use of domestic law to initiate a trade investigation against China is irresponsible, and its criticism of China is not objective," a Chinese Commerce ministry spokesman said in a statement to Reuters.

"China expresses strong dissatisfaction with the United States' unilateral protectionist action. We urge the U.S. side to respect the facts," the statement continued.

The spokesman went on to say the country would take "all appropriate measures, and resolutely defend China's lawful interests."

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China's alleged theft of U.S. technology, music, films and other intellectual property has plagued U.S. lawmakers in the past.

Beijing's response to the probe comes after U.S. trade Representative Robert Lighthizer Robert (Bob) Emmet LighthizerWhiskey, workers and friends caught in the trade dispute crossfire GOP senator warns quick vote on new NAFTA would be 'huge mistake' Pelosi casts doubt on USMCA deal in 2019 MORE announced the probe on Friday.

President Trump had given the Office of the U.S. Trade Representative approval to determine whether a probe into the matter was necessary.

The probe marks the administration's toughest action so far on Chinese trade practices.

Trump frequently blasted China's trade policies on the campaign trail, claiming that the U.S. was getting a bad deal from Chinese trade policy.

The new probe is expected to complicate relations with China, which is already strained after rising tensions over North Korea's nuclear and ballistic missile programs.