Turkey is pressing ahead with talks with U.S. and European firms over its first long-range missile defense system, as the preferred Chinese bidder has yet to meet all requirements for the multi-billion dollar project, two officials said on Thursday.

NATO member Turkey chose China Precision Machinery Import and Export Corp in 2013 as the preferred candidate for the $3.4 billion deal, prompting U.S. and Western concern about security and the compatibility of the weaponry with NATO systems.

Turkey’s defense minister said last week it did not plan to integrate the system with NATO infrastructure, only for the presidential spokesman to say days later that the systems would be integrated. […]