KEY POINTS
  • The United States has halted delivery of equipment related to the stealthy F-35 fighter aircraft to Turkey.
  • This marks the first concrete U.S. step to block delivery of the jet to the NATO ally in light of Ankara's planned purchase of a Russian missile defense system.
  • Turkish President Tayyip Erdogan has refused to back down from Ankara's planned purchase of a Russian S-400 missile defense system that the United States has said would compromise the security of F-35 aircraft.
A F-35 fighter jet is seen as Turkey takes delivery of its first F-35 fighter jet with a ceremony at the Lockheed Martin in Forth Worth, Texas, United States on June 21, 2018.

The United States has halted delivery of equipment related to the stealthy F-35 fighter aircraft to Turkey, marking the first concrete U.S. step to block delivery of the jet to the NATO ally in light of Ankara's planned purchase of a Russian missile defense system.

U.S. officials told their Turkish counterparts they will not receive further shipments of F-35 related equipment needed to prepare for the arrival of the stealthy jet, two sources familiar with the situation told Reuters on Monday.