Patriot missiles are an effective but expensive air defense system. Graphics show how they work.

The U.S. and Ukraine are disputing Russia’s claim that it destroyed an American-made Patriot missile defense system Tuesday during an airstrike on Kyiv.

Russia said a hypersonic Kinzhal missile destroyed the Patriot system, but U.S. officials said the Kinzhal was intercepted by multiple Patriot missiles. Officials said the Patriot system is still operational but sustained minor damage in the Russian attack.

The incident focused new attention on Patriot missiles, which began arriving in Ukraine in April. The missiles are considered one of the most effective U.S. air defense systems but are considered expensive and limited in supply.

Ukraine began asking for Patriots in August 2021, five months before Russia invaded Ukraine. The U.S. said in December 2022 that it would send a Patriot battery as part of a $1.85 billion assistance package to Ukraine, a move that was viewed as a strong commitment to the country.

Ukraine has two Patriot systems, one from the U.S. and another from Germany and the Netherlands.

What is the Patriot missile system?

The Patriot is a truck-mounted surface-to-air guided missile system. It started production in the 1980s and can target aircraft, cruise missiles and shorter-range ballistic missiles. It is constantly being updated, manufacturer Raytheon says.

The cost of supplying Patriot missiles to Ukraine is about $400 million for the system and $690 million for the missiles, a total of $1.1 billion, according to estimates from the Center for Strategic and International Studies.