Brussels unveiled the proposal on Tuesday as part of plans to revise its cybersecurity rules in a bid to bolster Europe's defences against a surge in cyber attacks.

It did not name any country or company as a target, but has taken an increasingly tough stance on trade issues with China, often citing security concerns.

China's foreign ministry spokesman Guo Jiakun told reporters on Wednesday the move amounts to protectionism by the bloc.

"We urge the EU to avoid going further down the wrong path of protectionism, otherwise, China will inevitably take necessary measures to resolutely safeguard the legitimate rights and interests of Chinese enterprises," Guo told a news conference.

The plans would see the European Union block third-country companies from European mobile networks if they are deemed a security risk, building on previous measures in 2023 that saw Chinese companies Huawei and ZTE excluded from networks.

Guo warned that the EU plans would again incur "huge" economic costs.

"It is naked protectionism. Behaviour that wantonly interferes in the market and goes against the laws of economics not only fails to achieve so-called security but also incurs huge costs," he said.

Brussels took the new step after the 2023 measures failed to yield enough change across the 27-country bloc.