By Diyar Guldogan

ANKARA

The purchase of S-400 missile defense system from Russia is not "worrying", Turkish President Recep Tayyip Erdogan said on Monday.

"Why would it be worrying? Every country needs to take certain measures for its own security," Erdogan told reporters at Ankara Esenboga airport.

Erdogan's remarks came a day after Joint Chiefs of Staff chairman, Gen. Joseph Dunford, labeled media reports about Turkey purchasing the S-400 system from Russia as "incorrect", saying: "That would be a concern, were they to do that, but they have not done that."

Erdogan said it was "important" for Turkey to choose an entity with which it could be in co-production.

He added that negotiations on the missile system had been "largely" completed.

Russian presidential aide Vladimir Kozhin said late June that Moscow and Ankara had agreed on the delivery of S-400 mobile systems but that the Kremlin had not approved a loan for the deal. 

The S-400 system was introduced in 2007 and can carry three types of missiles capable of destroying ground and air targets, including ballistic and cruise missiles.

It can track and engage up to 300 targets simultaneously and has an altitude ceiling of 27 kilometers (17 miles).