PRAGUE — In an attempt to push back against attempts to limit its reach in Europe, the Chinese technology giant Huawei threatened legal action against the Czech Republic if its cybersecurity agency did not rescind its warning about the risk the company poses to the nation’s critical infrastructure.

As nations across Europe take the first steps to reconfigure the systems that control the internet, Huawei’s threat was the latest salvo in the escalating war over who will control the hardware that will underpin the new 5G, or fifth-generation, networks.

For more than a year, the United States has been engaged in a global campaign aimed at limiting the reach of Chinese telecommunication firms, contending that they pose a threat to security.

While American officials have not offered specific details to support their concerns, they have pointed to China’s National Intelligence Law, passed in 2017. They say the law requires Chinese companies to support, provide assistance to and cooperate in Beijing’s national intelligence work, wherever they operate.

That law was one of the factors that led the Czech cybersecurity agency, Nukib, to issue a formal warning in December about the risk posed by Huawei and another Chinese technology firm, ZTE.

The warning, which carries the force of law, requires all companies in the Czech Republic that are deemed critical to the nation’s health to perform a risk analysis that takes security concerns into account.

It has already led several large companies and government ministries to distance themselves from Huawei, including barring the company from bidding on new projects.

On Friday, the Czech newspaper Dennik N published excerpts from a letter from Huawei to the head of the Czech cyber agency, Dusan Navratil, and Prime Minister Andrej Babis threatening legal action.

“Huawei cannot represent a cybersecurity threat as stated in the warning,” the letter said. “Huawei, according to the Chinese law, does not have any obligation to install backdoor or spyware into their products, and the company would never agree to such a request.”