More of the US-made rocket artillery systems Ukraine has been using to hammer Russian forces have arrived

• Four more US-made rocket systems arrived in Ukraine on Monday, officials confirmed.
• Ukraine now has 16 High Mobility Artillery Rocket Systems (HIMARS) in its possession.

Four more US-made High Mobility Artillery Rocket Systems (HIMARS) arrived in Ukraine on Monday, as the country continues to use the weapons to great effect against Russian forces in a fierce artillery fight in the east.

Ukrainian Defense Minister Oleksii Reznikov confirmed on Twitter that the HIMARS — long-range, precision weapons that can hit targets 50 miles away — arrived, and he expressed his gratitude toward the US.

"We have proven to be smart operators of this weapon. The sound of the #HIMARS volley has become a top hit of this summer at the front lines!" Reznikov wrote.

Andriy Yermak, an advisor to Ukrainian President Volodymyr Zelenskyy, tweeted to "Say HI" to the new HIMARS, and said they are "ready to speak up."

Monday's arrival of the four HIMARS brings the total in Ukrainian possession to 16. Though Ukraine had previously received M777 Howitzers from the US, the country repeatedly said it needed long-range rocket artillery. The first HIMARS delivery arrived in late June.

Military experts previously told Insider's Sinéad Baker that the weapons have "made such a massive difference" for Ukrainian forces as they continue to battle Russian troops in the eastern Donbas region, where the five-month-long campaign has largely become an artillery duel.

Ukraine claims it used HIMARS to destroy dozens of Russian ammunition depots and kill a top general, and officials have celebrated Ukraine's ability to use the weapons to curb Russian troop advancement.

Chairman of the Joint Chiefs of Staff Gen. Mark Milley said last month that HIMARS have been used "against Russian command-and-control nodes, their logistical networks, their field artillery near defense sites, and many other targets," and a senior US defense official said in late July that with the help of the HIMARS, Ukrainian forces were able to knock out over 100 "high value" Russian targets.

In his remarks in June, Milley noted that the rocket strikes were "steadily degrading" the efforts of Russian President Vladimir Putin's troops.