The Patriot missile system, created by the United States, is being used by Ukraine to counter the threat of Russian air strikes.
Three countries have sent the Patriot to Ukraine – the US, Netherlands and Germany.
Created by the United States, the Patriot system is used to intercept and destroy incoming cruise missiles and aircraft.
What is Patriot?
The MIM-104 Patriot system has given more than a dozen countries worldwide the power to destroy aerial threats on the battlefield.
Standing for the Phased Array Tracking Radar to Intercept on Target, the Patriot's batteries consist of eight launchers, each with the capacity to fire four missiles.
The system can track 100 threats from 60 miles away and its missiles cost $3m each and, despite having a long range, they are not primarily designed to defend entire cities.
The Pentagon confirmed the claim, but many commentators have cast doubt over this.
Days later, Russia claimed to have destroyed one of Ukraine's US-made Patriots - something Kyiv denied.