Turkey's Erdogan says Russia preparing S-400 systems for delivery

Speaking to reporters before leaving for Bosnia on Monday, Erdogan wouldn't say, however, when the Russian missile defense system would reach Turkey or where they will be deployed.

The delivery of the systems could bring Turkey closer to US sanctions. US officials have warned that Turkey would face economic sanctions as well as being expelled from a program to produce the F-35 fighter jets.

Sanctions would be devastating for Turkey's ailing economy.

Previous diplomatic crises with Washington have led to drastic dips in the value of the Turkish lira. A 30 percent decline in the currency prompted a recession last year, and the lira has fallen another 10 percent this year.

Even minor US sanctions could prompt another sharp slide in the currency.

Turkey has, however, refused to pull back from the deal.

Erdogan said: "The preparations for the journey, the loading (of the S-400) is continuing ... The S-400 will arrive by planes. May it be beneficial for our country, our region and especially for the world."

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