The United States has reacted with alarm to news that Turkey has chosen a Chinese company, slapped with US sanctions, to build its first long-range air defence and anti-missile system.
China Precision Machinery Export-Import Corp (CPMIEC) beat out competition from a US partnership of Raytheon and Lockheed Martin, Russia's defence, and the Italian-French consortium defence in the tender, worth $4bn according to Turkish media.
[The US has] conveyed our serious concerns about the Turkish government's contract discussions with a US-sanctioned company for a missile defense system that will not be interoperable with defence systems or collective defense capabilities.
Turkey is a key regional ally to the United States, and currently has US-built Patriot missile systems deployed on its border to deter incoming attacks from Syria.
CPMIEC has been hit by a series of US sanctions over the past decade, accused of selling arms and missile technology to Iran and Pakistan, meaning that all US groups and individuals are barred from doing business with it.
The US has "conveyed our serious concerns about the Turkish government's contract discussions with a US-sanctioned company for a missile defence system that will not be interoperable with NATO systems or collective defense capabilities," State Department spokeswoman Jen Psaki said on Monday.
"Our discussions will continue," she told reporters.
Turkey wants to build its own long-range air defence and anti-missile architecture to counter both enemy aircraft and missiles.
An official statement from Ankara last week said Turkey had "decided to begin talks with the CPMIEC company of the People's Republic of China for the joint production of the systems and its missiles in Turkey."
However, Turkey said on Monday it could still reconsider its decision to co-produce a long-range air and missile defence system with a Chinese firm currently under US sanctions, but said it felt no obligation to heed other countries' blacklists.
"We do not consider anything other than Turkey's interests," Turkish Deputy Prime Minister Bulent Arinc told reporters.
"It is not possible for another country to say, 'I have a problem with them, I had put them on a black list, a red list, how could you give them a tender?'" said Arinc, who also serves as the government's spokesman.
Arinc did not single out the US in his criticism, saying comments from US officials about the decision had been "respectful", but reiterated that Turkey did not need to consult on matters of domestic defence.
"We are a member of NATO and we have had good relations from the beginning with NATO countries, especially the United States.
However, when it comes to the subject of defending Turkey ... we have the power to take a decision without looking to anyone else," he said.
Arinc said that while the deal had not yet been completed, the initial selection had been based on the Chinese offer being the most economical and because some of the production would be carried out in conjunction with Turkey.
Psaki said the US has made clear its concerns to Turkey at a high level and had taken note of comments by Turkey that the deal was not yet final.
If a deal was finalised "then we will talk about that at that point," Psaki added.
In January, NATO began deploying Patriot missile system batteries to help protect Turkey from any spillover of the conflict in neighbouring Syria.
The Patriot missiles, effective against aircraft and short-range missiles, were provided by the United States, Germany and the Netherlands.