Both the US and UK have issued warnings about the Chinese technology and telecoms giant ZTE.

The decision by the US Commerce Department to ban American firms from selling equipment to ZTE for the next seven years dates back to a case from a few years ago, when ZTE was accused by the US government of violating sanctions against Iran.

At the time, the US said if ZTE refused to comply, there would be consequences.

This week, the US made good on those threats and is hitting ZTE where it hurts.

A shortage of US components is likely to cause ZTE to miss shipment deadlines and lose orders, according to investment firm Jefferies. It has cut its estimates for ZTE sales by 13.5% in 2018 and 7.6% in 2019.

ZTE's chairman Yin Yimin has reportedly said this is a "crisis" and called for his 80,000 strong staff to remain calm, according to a leaked memo seen by the South China Morning Post.

And it's not just the US.

In a seemingly unrelated case, the UK on Monday warned companies about doing business with ZTE