The Pentagon has put a Lockheed missile contract on hold until the company fixes flawed safety devices and assembles its newest interceptor missile, according to the head of the US Missile Defense Agency.

Lieutenant General Patrick O’Reilly said Lockheed will not receive the new missile defence contract until it rectifies and starts assembling the interceptors.

Lockheed is a year behind schedule for delivering the first 24 missiles, and is under a second contract to deliver another 24 missiles, according to Bloomberg.

The new contract, worth more than $400m, is for a third batch of missiles, O’Reilly said.

The interceptor is one of the main components of the new missile defence, which was planned to be deployed in the Middle East against Iran’s medium and long-range ballistic missiles.