US President Donald Trump signed into law a new defence spending bill which includes a clause preventing government agencies and contractors from using equipment supplied by Chinese vendors Huawei and ZTE.

The ban covers use of the vendors’ equipment as “substantial or essential component of any system,” though it is unclear whether it covers handsets in addition to network equipment. Regardless, the block applies to both new procurement deals and the renewal of existing contracts, taking effect over the next two years.

Additionally, the measure directs government agencies, including the Department of Commerce and Federal Communications Commission, to make funding available to help affected entities replace existing technology outlawed by the ban.

In a statement to Reuters, Huawei called the clause “ineffective, misguided and unconstitutional,” adding it “does nothing to identify real security risks or improve supply chain security”.

Not included in the final bill was an amendment which would have reinstated trade restrictions on ZTE.