Turkey would retaliate against what it called an unacceptable threat of U.S. sanctions over Ankara's purchase of Russian S-400 missile defenses, its foreign minister said on Monday, adding he thinks President Donald Trump wants to avoid such measures. Turkey began receiving deliveries of the surface-to-air S-400 systems earlier this month, prompting the United States to begin removing the NATO ally from its F-35 stealth fighter program over security concerns. Washington says it is concerned that S-400 software will compromise its F-35s to the benefit of Russia. While several Republican and Democratic US lawmakers have pressed for sanctions, Trump has equivocated in recent days. "If the United States portrays an adversarial attitude towards us, we will take retaliatory measures, as we've told them. This is not a threat or a bluff," Foreign Minister Mevlut Cavusoglu said in an interview with broadcaster TGRT Haber. "We are not a country that will bow down to those who show a animosity towards Turkey," he said, reiterating a threat of retaliation that Turkey made last month. Cavusoglu added that he did not expect the US administration to take such action. "Trump does not want to impose sanctions on Turkey and he frequently says that his administration and the previous US administration is also responsible for Turkey not being able to buy Patriot systems. This is true," Cavusoglu said. The United States announced last week it was beginning the process of removing Turkey from the program for the F-35 stealth jets, the most advanced aircraft in the U.S. arsenal, which is used by the North Atlantic Treaty Organization and other partner countries. Turkey, like some other NATO partners, was part of the manufacturing supply chain for the aircraft, producing some 900 parts and Turkish defense companies are set to lose work worth billions of dollars. A US official said it would cost some $500 million to $600 million to shift F-35 manufacturing from Turkey. The delivery of S-400 components is ongoing, with 14 shipments of related equipment having landed in Turkey over the last nine days. Deliveries are set to continue through April 2020. Separately, Sergei Chemezov, head of Russia's Rostec state conglomerate, said that Russia and Turkey were in talks about the possibility of jointly manufacturing some components of the S-400 system in Turkey. "Moscow and Ankara are holding consultations in the area of the licensed production of the S-400 air defense system component parts," Turkey's state-run Anadolu news agency quoted Chemezov as saying. "Besides, Turkey is interested in the latest Russian combat modules, air defense systems of various ranges, as well as anti-tank systems. Negotiations are underway for Russia to help the Republic of Turkey in creating its national air defense and long-range missile defense systems," he said. Chemezov added that Moscow was ready for various formats of technological cooperation, including in such high-tech areas as the aerospace industry, helicopter construction, and energy. — Reuters