First NATO country sends Ukraine powerful surface-to-air missiles to shoot down Russian aircraft and cruise missiles

• Slovakia said it sent Ukraine an S-300 air defense system to defend against Russian attacks.
• The Soviet-era S-300 is a long-range surface-to-air missile system that can shoot down cruise missiles and aircraft.

Slovakia Prime Minister Eduard Heger has confirmed that it had sent its S-300 air defense system to Ukraine, becoming the first NATO country to answer the calls by President Volodymyr Zelenskyy to supply powerful missile weaponry.

The S-300 is a Soviet-era long-range surface-to-air missile system that can shoot down cruise missiles and aircraft and has a range of up to 90 miles.

It is considered one of the most potent anti-aircraft missile systems and is in the arsenal of three NATO countries: Slovakia, Bulgaria, and Greece.

On Friday, the Slovakian prime minister wrote on Facebook that donating the system did not mean that Slovakia, a NATO country, has become a part of the armed conflict in Ukraine.

Zelenskyy has urged Western allies to send planes, tanks, and defense systems to Ukraine and mentioned S-300s during an impassioned speech to Congress by video last month.

"Russia has turned the Ukrainian sky into a source of death for thousands of people," Zelenskyy told Congress.

"You know what kind of defense systems we need, S-300 and other similar systems."

NATO countries have begun to step up their support of Ukraine by sending more heavy-duty weaponry as Russia's invasion continues.

The Czech Republic became the first NATO country to send tanks to Ukraine earlier this week, as a Czech defense source told Reuters.

NATO Secretary-General Jens Stoltenberg told AP on Thursday that individual NATO countries were planning to increase the supply of weapons to Ukraine following recent atrocities but did not provide details.

As an organization, NATO has refused to send weapons or troops to non-member Ukraine, but individual countries can choose to act.

The move follows recent reports about the death of at least 300 civilians in Bucha and a rocket attack on a train station in Kramatorsk that killed at least 50 people on Friday.

Zelenskyy warned that the predicted fighting in Donbas, eastern Ukraine, could result in the biggest war in centuries.

Speaking to the German newspaper BILD, owned by Axel Springer, Insider's parent company, on Friday, Zelenskyy predicted intense fighting in the coming days.

"It could be a big war in Donbas — like the world has not seen in hundreds of years," he told BILD reporter Paul Ronzheimer.

"We will go on defending our country until the end," the Ukrainian president continued.

The chilling forecast echoes what Ukraine's foreign minister Dmytro Kuleba told NATO members on Thursday.

"The battle for Donbas will remind you of the Second World War," Kuleba said.

He used this warning to immediately call on Western allies to provide more heavy weaponry, including air defense systems, artillery, armored vehicles, and jets.

Russian President Vladimir Putin's forces are regrouping for a new eastern offensive on the Donbas region after failing to capture Kyiv.

President Joe Biden said on Friday that the US was supporting Slovakia's decision to ship the S-300 missile system to Ukraine and was sending the Eastern European country a US-made Patriot missile-defense system as a replacement.

"I want to thank the Slovakian government for providing an S-300 air defense system to Ukraine, something President Zelenskyy has personally raised with me in our conversations," Biden said.

"Now is no time for complacency," Biden said in a statement while accusing the Russian military of committing "horrific acts of brutality."