Ukrainian President Volodymyr Zelensky on Tuesday pleaded for more air defense help to stop Russian attacks as he began an intense week of diplomatic meetings with Western partners.
"Russia's greatest strategic advantage over Ukraine is superiority in the sky. It is missile and bomb terror that helps Russian troops advance on the ground," Zelensky told a reconstruction conference in Berlin.
"Air defense is the answer," he said.
Zelensky, who is also due to address the German parliament, will join the heads of the G7 developed nations later this week in Italy.
He then heads to Switzerland for peace talks over the weekend on the war in Ukraine. Russia has not been invited.
Opening the Berlin conference, German Chancellor Olaf Scholz also urged allies to provide more air defense for Ukraine.
"I would like to make a heartfelt plea to everyone here today: please support our initiative to strengthen Ukraine's air defense with everything that is possible," Scholz told delegates.
"The best reconstruction is the one that doesn't have to take place at all," he said.
Germany is leading an effort called Immediate Action on Air Defense for Ukraine, and has contributed three Patriot systems to Kyiv.
But seven Patriots are needed for Ukraine to shield its urban centers from the storm of Russian missiles, said Zelensky, who warned that Moscow had already destroyed half of the country's electricity production since winter.
"As a result of the strikes of Russian missiles and drones, nine gigawatts of capacity have already been destroyed. The peak of electricity consumption last winter was 18 gigawatts. So the half now doesn't exist," Zelensky said.
After almost a year of stalemate, Ukraine has been forced to abandon dozens of frontline settlements this spring, with Russian troops holding a significant advantage in manpower and resources.
Ukraine's defense ministry said on Tuesday its forces had downed a Russian Su-25 jet a day earlier in the eastern Donetsk region, where Moscow has concentrated its firepower in recent weeks.
Ukrainian prosecutors in the industrial region, which the Kremlin claimed to have annexed in late 2022, meanwhile said five people had been wounded in an overnight Russian strike on the frontline town of Kostyantynivka.
Russian missile and drone barrages, including a major attack over the weekend, have stretched Ukraine's air defense capacity.
Ukrainian officials have warned of more and longer power outages as generating capacity has been severely hit by Russian attacks.
With the war at a critical juncture, Zelensky is ramping up a diplomatic offensive to shore up support.
At the G7 in southern Italy, he will attend a discussion Thursday on Russia's war on his country, where he will have another opportunity to press Western leaders for more help.
Turkey President Recep Tayyip Erdogan and India's Narendra Modi will both be in attendance on the invitation of Italian Prime minister Giorgia Meloni alongside G7 leaders.
US President Joe Biden will however be absent from the summit in Puglia, where he will instead be deputized by Vice President Kamala Harris.
G7 leaders hope to agree a deal on using the profits from the interest on 300 billion euros ($325 billion) of frozen Russian central bank assets to help Kyiv.
The leaders are also expected to discuss their concerns over China's support for Russia's military expansion.
After the G7 meeting Zelensky will head to Switzerland, where he will attend a peace summit on the war in Ukraine from Saturday.
The gathering, hosted at the luxury Burgenstock resort on a mountain ridge overlooking Lake Lucerne, is set to be attended by representatives from some 90 countries and international organizations.
Organized at Ukraine's request, the outcome remains uncertain, though Switzerland is hoping to secure a joint final declaration.
Russia was not invited to the summit in Switzerland and Moscow's key ally China has said it will not attend.
The Kremlin has repeatedly indicated it will not participate in any negotiations if Kyiv does not accept Moscow's annexation of the approximately 20 percent of Ukrainian territory Russia currently occupies.
As for China, Swiss officials lobbied Beijing to participate without success.
"It's difficult for China to participate at the moment", Swiss Foreign minister Ignazio Cassis said, adding that Beijing had hitherto "really helped give us a hand on this journey".