U.S. missiles were secretly deployed to Ukraine in recent days

Ukraine has long sought ATACMS, a surface-to-surface missile that can strike well behind Russian lines and that can be fired by the Himars, or High Mobility Artillery Rocket System launchers, the U.S. has provided the country.

The ATACMS models that were provided have a range of about 100 miles.

     NOTE: Wikipedia does not agreed — it says the ATACMS has a range of up to 190 miles (300 km)

     RELEVANT : The distance from Moscow to the nearest point on the Ukraine border is about 450 kilometers (280 miles) to the northeast.

     REMINDER : MOSCOW, September 13. /TASS/. Russia’s response to potential US deliveries of its ATACMS missiles to Ukraine would not be long in coming, said Konstantin Gavrilov, head of the Russian delegation to the Vienna talks on military security and arms control.

Yuriy Ihnat, the spokesman for Ukraine’s Air Force, said that long-range strikes against Russian air bases are a crucial part of Ukraine’s broader strategy of weakening Russian forces as Ukraine continues its counteroffensive.

https://www.wsj.com/world/europe/ukraine-fires-atacms-missile-at-russian-forces-for-the-first-time-3bebcdb1?