By Hannah Rabinowitz, CNN

(CNN) — FBI Director Christopher Wray on Wednesday is expected to warn that Chinese hackers are preparing to “wreak havoc and cause real-world harm” to the US.

“China’s hackers are positioning on American infrastructure in preparation to wreak havoc and cause real-world harm to American citizens and communities, if or when China decides the time has come to strike,” Wray will tell the House Select Committee on the Chinese Communist Party, according to a copy of his remarks shared with CNN.

The warning marks Wray’s most direct public warning to date about the threat that Chinese hackers pose to critical infrastructure nationwide. The head of the National Security Agency and other senior US officials are also set to testify on Chinese cyber activity in front of the panel Wednesday.

PRC hackers, Wray will say, are targeting things like “our water treatment plants, our electrical grid, our oil and natural gas pipelines, our transportation systems.”

The FBI and Justice Department have previously stressed their focus on preventing malign campaigns by the Chinese government and hackers.

CNN has reported that in recent months, federal law enforcement has used a court order to allow the Justice Department to update vulnerable software used by thousands of devices in the US that are at the center of a Chinese hacking campaign targeting sensitive US critical infrastructure. Nevertheless, the hackers are believed to be deeply entrenched in US infrastructure.

The move by the Justice Department and FBI is part of a broader, government-wide attempt to blunt the impact of a persistent Chinese hacking effort that US officials fear could hinder any US military response in the event of a Chinese invasion of Taiwan, CNN has reported. The hackers are believed to be using access to some of the devices to burrow further into sensitive critical infrastructure — things like ports and transportation networks.

The Chinese government has previously denied allegations of hacking efforts.

Wray will say Wednesday that the PRC’s efforts extend beyond technology, his remarks show, warning that “they target our freedoms, reaching inside our borders, across America, to silence, coerce, and threaten our citizens and residents.”

As CNN exclusively reported Tuesday, Chinese leader Xi Jinping told President Joe Biden when the two men met in November that China would not interfere in the 2024 US presidential election. That assurance was reiterated by the Chinese foreign minister to Biden’s national security adviser this past weekend, two people familiar with the conversations told CNN.

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