Turkey could scrap a controversial plan to buy missile defence systems from China that alarmed the United States and its Western allies, Turkish and European sources said Wednesday.

Key NATO member Turkey said in September last year it was entering negotiations with the China Precision Machinery Export-Import Corporation (CPMIEC) to acquire its first long-range anti-missile systems.

But the plan has deeply concerned the United States, which has already imposed sanctions on the Chinese company for supplying arms to Iran and Syria in defiance of an embargo.

"Several options are on the table, including a cancellation of the tender" that was won by the Chinese company, a Turkish government source familiar with the issue told AFP, asking not to be named.

Turkey chose CPMIEC in preference to offers from US firms Raytheon and Lockheed Martin, as well as Russia's defence exporter Rosoboronexport and the French-Italian consortium Eurosam.

The contract is valued at 2.9 billion euros ($3.6 billion).

Aside from strategic concerns, Turkey's allies in NATO also expressed worry about the compatibility of the Chinese systems with their own missile defence systems.

But Turkey had already admitted to difficulties in negotiations with the Chinese side, notably on the transfer of technology and issues of joint production.

Joint production is a crucial part of the planned deal as Turkey wants to build its own long-range air defence and anti-missile architecture to counter both enemy aircraft and missiles.

Turkey was supposed to have announced its final decision in summer but then invited the Chinese company's rivals to present revised offers.

"We have received information that Turkey is preparing ultimately to launch a new tender to negotiate as a priority with European and American firms," a European source in Ankara told AFP.

The Chinese embassy declined to comment.

Turkey had previously defended its decision to enter into talks with the Chinese company but said it is open to new bids should the negotiations fall through.

President Recep Tayyip Erdogan said in September that talks were continuing with the Chinese side but said that the French consortium was "second on the list" and had come up with a new offer.