Two US officials said on Tuesday that a Russian strike likely damaged a Patriot missile defense system employed by Ukraine, but that it did not appear to have been destroyed.

The Patriot system is one of a slew of powerful air defense systems delivered by the West to assist Ukraine in repelling a Russian air attack campaign that has targeted important infrastructure, power plants, and other locations.

One U.S. official, speaking on the condition of anonymity and citing initial information, said Washington and Kyiv were already talking about the best way to repair the system and at this point it did not appear the system would have to be removed from Ukraine.

The official added that the United States would have a better understanding in the coming days and information could change over time.

The Patriot is considered to be one of the most advanced U.S. air defense systems, including against aircraft, cruise missiles and ballistic missiles. It typically includes launchers along with radar and other support vehicles.

Russia’s defense ministry said on Tuesday that it had destroyed a U.S.-built Patriot surface-to-air missile defense system with a “hypersonic” Kinzhal missile in an overnight strike on Ukraine.

Ukraine said earlier that it had shot down 18 Russian missiles overnight, including an entire volley of six Kinzhals. When asked about the Ukrainian claim, Russian Defense Minister Sergei Shoigu dismissed it, the RIA news agency reported.

It was not clear which Western weapon Ukraine used. The Pentagon had no immediate comment.