WASHINGTON : The US Congress is set to adopt a law next week forbidding Turkey from using American funds to acquire a $4 billion missile system from a Chinese company blacklisted by Washington. The US has voiced deep concern over Turkey’s decision in September to enter negotiations with China Precision Machinery Export-Import Corporation for its first long-range anti-missile system.

CPMIEC,  is under US sanctions for selling arms and missile technology to Iran and Syria. Turkey’s move also irritated its allies in NATO, which has said missile systems within the transatlantic military alliance must be compatible with each other. The annual US defense authorization bill contains a clause barring the use of “2014 funds to integrate missile defense systems of the People’s Republic of China into US missile defense systems.”

“Such a system would not be compatible with, and should not be integrated with, missile defense systems of the North Atlantic Treaty Organization,” the Senate and House Armed Services Committees said.

Without US subsidies, the cost for Turkey to install the Chinese missiles becomes steeper.

The bill is expected to be approved in the Senate next week, before being signed into law by President Barack Obama.

CPMIEC beat competition from a US partnership of Raytheon and Lockheed Martin, Russia’s Rosoboronexport, and Italian-French consortium Eurosam for the multibillion-dollar deal.

These companies have until January 31 to submit new bids.

Turkey will make its final decision by mid-2014.