A California man confessed to helping the North Korean regime prepare for an attack in a “sophisticated scheme” to illegally obtain restricted weapons and military grade technology, federal prosecutors announced Tuesday.

Shenghua Wen, a Chinese national residing unlawfully in Ontario, California, conspired with North Korean officials to obtain prohibited items before traveling to the US as a student in 2012, the Justice Department alleged in a criminal complaint. Wen, who allegedly overstayed his visa and remained in the US illegally, was arrested Tuesday by the FBI.

During interviews with the FBI, Wen said “he believed the North Korean government wanted the weapons, ammunition, and other military-related equipment to prepare for an attack against South Korea,” according to the complaint, which adds the North Korean government paid Wen $2 million to obtain the items.

In addition to weapons and equipment, Wen told investigators the North Korean regime also tasked him with obtaining military uniforms in the US, which “would subsequently be used by the North Korean military to disguise their soldiers to conduct a surprise attack on South Korea,” the complaint states.

Thousands of US military personnel are stationed in South Korea to help bolster security and stability in the region. Justice Department officials said the arrest was unrelated to Tuesday’s internal political turmoil amid a declaration of martial law and clashes outside South Korean parliament.

Prosecutors allege Wen established an export company in Texas, where firearms and ammunition were procured and transported to the Los Angeles area, then ultimately packed in cargo containers bearing fake inventory manifests for shipment to North Korea as recently as 2023.

While executing a search warrant at Wen’s home, authorities seized 50,000 rounds of ammunition, sophisticated chemical detection equipment, and a tool used for detecting listening devices, which Wen allegedly said he intended to also ship to North Korea.

During a search of his cell phone, the FBI discovered numerous messages “between Wen and several (North Korean) co-conspirators with images of firearms and electronic devices,” the complaint states.

“There is no telling what additional damage Mr. Wen could have committed if not for the intervention of law enforcement,” said US Attorney Martin Estrada during a news conference Tuesday.

CNN is attempting to locate attorney information for Wen. If convicted of violating the International Emergency Economic Powers Act, he faces up to 20 years in prison, Estrada said.

“The consequences of these actions cannot be overstated when technology and sensitive items fall into the wrong hands, especially those of hostile nations,” said Shawn Gibson, special agent in charge of Homeland Security Investigations.

Akil Davis, head of the FBI’s Los Angeles division, said: “Not only did the investigative team prevent additional restricted items going to the North Korean regime, but they gathered valuable intelligence for the United States and our allies.”