The US-made Army Tactical Missile Systems (ATACMS) that Washington has been supplying to Ukraine in recent weeks were shot down four times over Crimea, according to the Russian Ministry of Defense on Saturday.
Later, the ministry reported that over the previous week, 15 ATACMS had been shot down by Russian planes and air defense systems.
Russian sources stated on Tuesday that six of Ukraine's ATACMS attacks on the seized peninsula were shot down in an effort to breach Russian air defenses.
Last month, an American official stated in Washington that the US had been covertly sending long-range missiles to Ukraine in recent weeks.
With a maximum range of 300 kilometers (190 miles), the ATACMS missiles were initially fired against a Russian airfield in Crimea that was roughly 165 kilometers (103 miles) from the Ukrainian frontlines early on April 17, according to the official.
At first, the Pentagon was against the long-range missile deployment because they believed that removing the missiles from US arsenal would impair military readiness in the country.
Additionally, there were worries that Ukraine might use them to strike targets located far within Russia, which could escalate the conflict and result in a direct conflict between Russia and the US.
Separately on Saturday, the Russian ministry of defense announced that its forces had destroyed a military train that was transporting weapons and equipment made in the West and provided to Ukraine by NATO during the past week.
The precise date, location, and extent of the destruction were not made public.
Reports from either side of the battlefield are not immediately able to be verified by Reuters.
With a sharp backlash from Moscow, British Foreign Secretary David Cameron pledged on Thursday to provide Ukraine with 3 billion pounds ($3.7 billion) in annual military aid for "as long as it takes," saying that London has no problem with its weaponry being deployed inside Russia.