The following are the main points made by a senior US defense official to reporters on Friday at Day 44: The US sends the Patriot system to Slovakia Following repeated calls from Ukraine for assistance against Russian airstrikes, Slovakia is sending its only S-300 surface-to-air missile system to Ukraine, it announced on Friday, and at the same time, the United States announced that it was moving one of its Patriot rocket batteries in Slovakia to replace it. In this archive photo taken on December 13, 2013, an S-300 PMU-1 anti-aircraft missile is fired during a Greek military exercise near Chania on the island of Crete. “Under my guidance, and at the invitation of Slovakia, the US European Command will reposition a Patriot missile system, manned by members of the US forces, in Slovakia,” Defense Secretary Lloyd Austin said in a statement on Friday. “The duration of their development has not yet been determined, as we continue to consult with the Slovak government on more permanent air defense solutions.” There has been talk of such a settlement since last month, when Slovak Defense Minister Jaroslav Nad said his country was ready to deliver Soviet-era S-300s to Ukraine on the condition that Slovakia’s air defense capability be completed immediately. “If there is a situation where we have a suitable replacement or if we have a guaranteed capacity for a certain period of time, then we will be willing to discuss the future of the S-300 system,” said Slovak Prime Minister Eduard Heger in a joint statement. press conference with Austin on March 17. A US-based Patriot US military battery was pre-installed in Poland for this purpose and the system will soon be transported from Poland to Slovakia to replace the S-300, according to a senior US defense official. The Slovak Army has previously stated that it had about 45 missiles for the S-300 system. The United States “does not buy” Russia’s refusal to strike at the railway station Whitewashed cars are pictured outside a train station in Kramatorsk in eastern Ukraine, which was used to evacuate civilians after a rocket attack that killed at least 35 people on April 8, 2022. The Pentagon “does not buy” the denial of responsibility from Russia, said a senior US defense official. “They initially claimed a successful strike and then withdrew it only when there were reports of civilian casualties,” the official said. “It is our full expectation that this was a Russian strike – we believe they used a short-range ballistic missile, an SS-21.” Why might the Russians have targeted it? The official said the station is an important railway junction in a “very strategic location”, just south of the central city of Izyum. “And now we talk for days and days about how Izyum was so important to them because it’s almost in the middle of the Donbas,” the official said. Russian units “eliminated” Some of the Russian regular battalion (BTG) groups that have retreated behind the Belarussian-Russian border have been virtually killed in fierce fighting in Ukraine, according to a senior defense official. “We have seen indications of some units being literally eliminated for all intents and purposes. There is nothing left of the BTG except a handful of troops and perhaps a small number of vehicles,” the official said. In terms of total losses – counting troops, tanks, aircraft and missile stockpiles – Russia has lost between 15-20% of the combat power it had originally lined up against Ukraine since the invasion, according to the official. Russia hopes to recruit 60,000 new troops Some of the Russian forces that withdrew from Kyiv and elsewhere are now heading for the Russian cities of Belgorod and Valuyki, northwest of the Donbas. But there are no “indications” that new troops are waiting there to join them. At present, the decommissioned Russian BTGs, which typically consist of about 800-1,000 troops, are “exploring the option” of uniting, joining the remaining forces and supplies to form new units. “It will really depend on the unit and how ready they are to get back in the race, but we generally do not think this will be a quick process for them, given the type of losses they have suffered and the type of damage they have suffered in the standings. their units “, said the official. Russia also aims to recruit more than 60,000 new troops, according to the official. A Ukrainian soldier stands among damaged Russian tanks in Bucha, Ukraine, April 6, 2022. “They hope to be reinforced with new conscripts – there is a whole new recruitment program coming here in May,” the official said, adding that Russian conscripts have been serving for one year. “It remains to be seen how successful they will be in this, and where this aid will go, how much training they will receive,” the official said. In addition, the US sees signs that Russia has begun mobilizing reserves. After the reconstruction of the Russian BTGs, “the most likely course of action would be to move immediately south, right in Donbass,” the official said. The Pentagon estimates that more than 40 Russian BTGs are already stationed in or near the Donbas area. The estimate was “over 30” on Wednesday, which means that up to 10,000 additional soldiers have arrived in recent days. ABC News’ Luis Martinez contributed to this report.