And another arms sale. Russian-made S-400 air defense systems are expected to arrive in Turkey later today. They are capable of destroying targets at a distance of up to 400 kilometers. The United States has threatened Ankara with sanctions over the purchase, but Turkish President Recep Tayyip Erdogan says the US president spoke of no sanctions when they met in Osaka last month. Michal Bardavid reports from Mugla.

In 2017, Turkey agreed to buy an S-400 missile defense system from Russia reportedly worth 2.5 billion dollars. On Monday, Turkish President Recep Tayyip Erdogan confirmed that the missile shipment was proceeding as planned with Russia without mentioning a specific timeline and said this before traveling to Bosnia-Herzegovina for the Balkans summit. 'We hope for this to be beneficial to our country, our region and the world.' Ankara has been stressing that Turkey needs a missile defense system for its national security.

VEYSEL KURT, SECURITY EXPERT SETA FOUNDATION "When you look at the regions surrounding Turkey, you can see that threats have increased over the last five years. In the last one or two years, risks coming from Eastern Mediterranean and Aegean have increased and this has caused Turkey to take action in order to increase its military capacity."

The controversial deal is a major source of conflict with Washington.

MICHAL BARDAVID MUGLA, TURKEY "U.S. officials have repeatedly called on Turkey to withdraw from its deal with Russia. Washington insists the S-400 will compromise the F-35 fighter jets and has threatened to expel Turkey from the program."

The arrival of the S-400 is expected to trigger sanctions from Washington under the Countering America's Adversaries through Sanctions Act (CAATSA). The U.S. has already halted the F-35 training of Turkish pilots and insists Ankara will not be allowed to have both systems. However, Erdogan received some supportive words from U.S. President Donald Trump during the G20 summit last month in Osaka, Japan. Trump stated that Turkey was treated unfairly by the Obama administration when Ankara was seeking to buy the Patriot missile system. 

Erdogan interpreted these words as an assurance that the U.S. would not impose sanctions - however, since then several U.S. officials have reiterated their threats of sanctions. Previously one of Turkey's requests from the U.S. regarding a missile system was to include the transfer of technology as part of the deal. One security expert explains why this is significant for Ankara.

VEYSEL KURT, SECURITY EXPERT SETA FOUNDATION "When you don't transfer the technology, you become dependent on the country you buy the system from, you don't acquire the capacity to develop it. It just becomes an interface you can use, we're talking about a scenario where the trigger may not even be in your hands."

In 2018, the U.S. had imposed sanctions on Turkey following a political dispute which negatively affected the Turkish economy. Turkey is now bracing for potential U.S. sanctions and their impact. Michal Bardavid, CGTN, Mugla Turkey.