Ukrainian Defense Minister Oleksii Reznikov has said his country has received a delivery of High Mobility Artillery Rocket Systems, or HIMARS.
Reznikov revealed the arrival of the long-range rocket systems in a Twitter post on Thursday.
He expressed gratitude for "these powerful tools." He added that summer will be hot for Russian occupiers, and it will be "the last one" for some of them.
The United States provided the HIMARS at Ukraine's request.
The multiple rocket launchers have a longer range than those currently used by the Ukrainians, and are said to enable attacks with greater precision.
In a TV interview aired on June 5, Russian President Vladimir Putin warned Western nations that his country will strike facilities if long-range rocket systems are supplied to Ukraine.
The range of the newly provided systems is reported to be up to around 80 kilometers.
US officials said Ukraine has given them assurance it will not use the weapons to strike targets inside Russia.
In an essay published in the New York Times on May 31, US President Joe Biden said, "We are not encouraging or enabling Ukraine to strike beyond its borders."