The Pentagon said it will "rush" Patriot air defense missiles and artillery ammunition to Ukraine as part of its new military aid package. However, Patriot systems for launching the missiles will not be sent, Defense Secretary Lloyd Austin said. Ukrainian President Volodymyr Zelensky said Patriots were "urgently" needed to face a growing Russian air threat and "can and should save lives right now". On Saturday, Ukraine said Russia had carried out another massive air attack. Authorities in Kharkiv said a hospital was damaged. Energy facilities in three regions were attacked, Energy Minister German Galushchenko said. Russia attacked with cruise missiles, S-300 surface-to-air missiles and Iskander ballistic missiles, Ukraine said, adding that 21 were downed using aircraft, air defense systems and jamming. Ukraine claimed to have hit two Russian oil refineries across the border. Footage from one in the Russian region of Krasnodar appeared to have caused a large explosion, though local authorities denied significant damage. Russian authorities said on Saturday they had shot down some 68 Ukrainian drones over Russian territory. Speaking on Friday, Austin told a news conference that the US was committing to its largest security assistance package to date and would "move immediately" to get the supplies to Ukraine. The US was using $6bn (£4.8bn) for this purpose, he said. A source confirmed to the BBC that the $6bn was part of a $60bn aid package signed into law by US President Joe Biden on Wednesday, which also includes $1bn in more immediate aid. The assistance would include air defence munitions, counter-drone systems and artillery ammunition but not Patriot missile systems. "It"s not just Patriots that they [the Ukrainians] need, they need other types of systems and interceptors as well," Austin said. "I would caution us all in terms of making Patriot the silver bullet." Austin added that he was confident that more of the missile systems would be made available for Kyiv soon. Conversations were ongoing with European partners, he said, to deliver additional capabilities. The Chairman of the US Joint Chiefs of Staff, Gen. Charles Brown, said the assistance should eliminate the Ukrainians" need to ration shells on the frontline. Some of the latest funding would also go to building up Ukraine"s own defense industry, so that it can start manufacturing more of the ammunition it desperately needs. Austin said Russia had already increased domestic production of artillery ammunition and other weapons - as well as being propped up by supplies from Iran and North Korea. "Understand what"s at stake for Ukraine, for Europe, and for the United States," he said. "If Putin prevails in Ukraine - Europe would face a security threat it hasn"t seen in a lifetime. Russia will not stop in Ukraine." Asked whether the US aid would protect Ukrainian forces, Mr Austin said that the commitment was "material, real, and substantial" although "not instantaneous". "It"s going to take some time to get it in there and distribute. The Ukrainians were able to hold — with this capability, they can do a lot better." The defense secretary"s words came as Ukraine warned on Friday that Russia was ramping up attacks on its railways. A Ukrainian security source told the AFP news agency that Moscow wanted to damage Ukrainian railway infrastructure to "paralyze deliveries and movement of military cargo". Ukraine only has a handful of Patriots to complement other Western missile defense systems and existing stocks of Soviet-era surface-to-air missiles (SAMs), such as the S-300. The Patriots are the most capable and expensive air defense systems that Ukraine has. Each Patriot battery costs around $1bn (£800m), and each missile costs nearly $4m. Germany has already promised an extra Patriot system — and its defence and foreign ministers appealed to their European counterparts earlier this month to respond urgently. Greece has stocks of Patriots and S-300s but said none could be spared. "We explained why we cannot do it," Greek Prime Minister Kyrios Mitsotakis told Skai TV. His said his country"s air defenses were "critical systems for the protection of Greek air space". According to reports, Spain will supply some Patriot missiles but not a full system. Recent months have seen Kyiv step up its calls for Western assistance as its stocks of ammunition are depleted and Russia makes steady gains. Ukrainian officials have blamed delays in military aid from the US and other Western allies for the loss of lives and territory. — BBC