US officials are fanning out across Europe to warn about the security risks of allowing Chinese telecoms giant Huawei to help build 5G mobile networks, a US diplomat said Tuesday.

Washington considers the matter urgent as European Union countries prepare to roll out fifth-generation networks that will bring near-instantaneous connectivity, vast data capacity and futuristic technologies.

“We are urging folks not to rush ahead and sign contracts with untrusted suppliers from countries like China,” a US State Department official told reporters in Brussels.

The official said he was meeting EU officials as well as those in Belgium, France and Germany, while colleagues will be travelling to Spain and elsewhere to underline US concerns.

“Going with an untrusted supplier like Huawei or ZTE will have all sorts of ramifications for your national security,” he warned, speaking on condition of anonymity.

It could also undermine intellectual property protection, privacy and human rights, he added.

He said Washington’s priority was warning Europe where strong alliances make the “national security component even more compelling from the US point of view.”

In December, European Commission Vice President Andrus Ansip echoed US warnings about the threat posed by Huawei and ZTE who — under a 2017 Chinese cybersecurity law — are required to cooperate with Beijing’s intelligence services.

Speaking on Tuesday, Ansip said the Commission, the European Union’s executive arm, can play a limited coordinating role.

“National security is up to the member states,” the former Estonian premier told reporters.

“If the member states ask to coordinate, to take the common approach, then historically the Commission has always done so. We will do so if asked,” Ansip said.

Huawei strenuously denies its equipment could be used for espionage.