President Biden is expected to sign an executive order on Wednesday that will strengthen the government’s ability to respond to maritime cybersecurity threats, amid heightened concerns that China could seek to hobble crucial infrastructure systems within the United States.

Anne Neuberger, the deputy national security adviser for cyber and emerging technology, previewed the executive order for reporters on Tuesday evening, saying it would broaden the powers of the Department of Homeland Security.

She said that the order would also allow the U.S. Coast Guard to outline rules for establishing minimum cybersecurity requirements at ports throughout the United States, and that the government would invest $20 billion in port infrastructure as part of Mr. Biden’s infrastructure agenda. The order would give the Coast Guard the ability to control the movement of vessels that present threats and require ports and waterfront facilities to correct known or suspected cyberthreats.

The announcement of the initiative comes as American officials, including the F.B.I. director, warn that Beijing may seek to start an extensive hacking operation geared at taking down the United States’ power grid, oil pipelines and water systems in the event of a conflict over Taiwan. On Tuesday, officials said the initiative was not a response to any specific threat.

Ms. Neuberger said the executive order was a shift from “requesting to requiring” that the country’s shipping ports, which support 31 million jobs and serve as main entry points for international cargo, assess any cybersecurity risks and report them to government agencies, including the F.B.I. and the Cybersecurity and Infrastructure Security Agency.

But officials did not say how the new rules establishing a base line for safe cybersecurity operations would be enforced at ports, or what would happen if companies broke them.

The executive order also addresses long-running concerns by watchdogs that many of the shipping cranes at American ports that were manufactured by China could be manipulated to disrupt U.S. supply-chain operations.

Rear Adm. John C. Vann of the Coast Guard told reporters that the agency was assessing 200 cranes across the United States for cybersecurity vulnerabilities. He said about half of them had been evaluated, but he did not share what officials had found.

“By design these cranes may be controlled, serviced and programmed from remote locations,” he said, noting that those features potentially left Chinese-made manufacturing cranes “vulnerable to exploitation.”