LONDON: Chinese telecoms giant Huawei urged Britain on Wednesday not to rush into taking any costly decision to phase out its equipment from the UK's 5G network because of US sanctions.

The plea followed reports of Prime Minister Boris Johnson receiving a damning security agency reassessment about the long-term safety of Huawei.

The British review was triggered by US sanctions in February that blocked Huawei's access to US chips and semi-conductors at the heart of 5G networks.

Johnson's government allowed Huawei to roll out up to 35 percent of Britain's 5G network under the condition that it stays out of "core" elements dealing with personal data.

But the new sanctions raised the possibility of Huawei having to switch from trusted US suppliers to alternatives whose safety could not be guaranteed by UK security agencies.

Huawei vice-president Victor Zhang said the long-term impact of the US sanctions will take months to fully understand.

"We urge the UK government to take more time," Zhang told a conference call.

"What we are talking about is the long-term impact. It takes time. It takes months to understand."

Zhang said any decision to simply cut Huawei out of the speedy new network's development could delay nationwide 5G access for up to 18 months.

He estimated that a two-year delay would cost the UK economy £29 billion ($35.8 billion, 31.8 billion euros).

"The decision will impact the future of Britain's digital strategy and Britain's digital economy - it is so important," Zhang said.

Johnson is coming under growing political pressure to dump Huawei and adopt a tougher line with China for its treatment of Hong Kong and repression of ethnic Uighurs in the western Xinjiang region.

But Johnson also pledged last year to bring broadband access to all Britons by 2025.

Huawei equipment is already ubiquitous in Britain's older-generation 3G and 4G networks.

The Chinese company argues that 5G will become even more important as the world switches to home working because of the new coronavirus.

British telecoms companies have warned that stripping out all existing Huawei equipment could cost them billions and take years to implement.

It could also undermine Johnson's "full fibre for all" pledge.

Zhang said Huawei wanted to work with British telecoms providers and come up with safe alternatives to US equipment that could allay security concerns.

"We want to be clear that we will work to address any restrictions imposed on us," Zhang said.

He stressed that existing networks would not be affected by sanctions because their development is planned years in advance.

Huawei also has equipment stockpiles designed to cover immediate needs.

And he made an indirect reference to Johnson's broadband access pledge.

"This is a once-in-a-lifetime opportunity for Britain to take the lead in 5G," Zhang said.