President Donald Trump “tore into” UK Prime Minister Boris Johnson in a phone call last week after Britain announced it would allow Huawei into its 5G networks, according to a person familiar with the call.

The decision rejected longstanding US concerns about the Chinese tech giant. Trump was furious, according to the person, who said Trump berated Johnson over the move, which he characterized as a national security threat.

The Financial Times first reported on the phone call.

Officially, the US maintains a regretful tone about the decision, but the call reflects Trump’s more voracious private anger.