Ukrainian President Volodymyr Zelensky warned European leaders on Thursday that Russia could rebuild its military capabilities and attack other countries within five years if the continent were to waver in its support for Kyiv.
Zelensky, attending a summit of the European Political Community in Spain, also said he remained confident of continued US and European financial aid despite "political storms" in Washington and elsewhere.
In an emotional speech, Zelensky described how Ukrainian children in the eastern city of Kharkiv were learning remotely or attending classes in subway stations because of air raids.
"Until there is a fully effective air defence system, children cannot attend school," he told the gathering in the city of Granada, some 4,000km west of Kharkiv.
Underlining the horrors of war, a Russian attack on a village in the Kharkiv region on Thursday killed at least 49 people, including a six-year-old boy, Ukrainian officials said.
Zelensky said that by providing additional military equipment to Ukraine, European countries could help ensure that a "drone, tank, or any other Russian weapon will not strike anyone else in Europe".
"We must not allow (Russian President Vladimir) Putin to destabilize any other parts of the world and our partners in order to ruin Europe's power," Zelensky said.
"The presence of Russia, its military or proxies in the territory of any other country is a threat to all of us. We must work together to push Russia out of the territory of other countries," he added.
The European Political Community was established last year following Russia's invasion of Ukraine to foster cooperation among more than 40 countries from Norway to Moldova.
The Granada gathering gives leaders such as French President Emmanuel Macron, German Chancellor Olaf Scholz and British Prime Minister Rishi Sunak a chance to re-state their commitment to Ukraine after political turbulence in both the US and Europe raised questions about continued support.
A dispute among the Republican majority in the US House of Representatives has complicated budget negotiations and prompted President Joe Biden, a Democrat, to go from confidence that a deal will be made on Ukraine aid to openly expressing concern.
Support in Europe has also appeared less rock-solid after pro-Russian former prime minister Robert Fico won an election in Slovakia last weekend on pledges to end military aid to Ukraine.
Zelensky played down such concerns, saying: "I am confident in America. They are strong people with strong institutions, and a strong democracy."
The head of the European Commission, the EU executive, Ursula von der Leyen, said the bloc was working on a €50 billion (about RM249.2 billion) Ukraine package for 2024-2027, adding that she was "very confident" about continued US help for Kyiv.
Individual countries also made pledges in Granada.
Zelensky said on X, formerly Twitter, that he had discussed with Spanish Prime Minister Pedro Sanchez, the summit host, a new military aid package, energy assistance, and how to keep open a corridor in the Black Sea for Ukrainian grain exports.
A Spanish government source said Madrid would provide air defence and anti-drone systems to Ukraine as well as training for Ukrainian soldiers in how to use them.
Russia pulled out of a deal in July that had allowed Ukraine - a leading global grain exporter - to safely ship food products out via the Black Sea.
Russia has so far rejected UN overtures to revive the deal, while Ukraine is continuing some exports via what it calls a temporary "humanitarian corridor" for cargo vessels.
Ukraine's efforts to export grain overland via EU countries have caused tensions with Poland and some other eastern members of the bloc that are keen to protect their own farmers. Kyiv and Brussels are also discussing expanding alternative sea routes.
The summit will also discuss efforts by Ukraine and others to join the EU as well as how to tackle increasing arrivals of refugees and migrants from the Middle East and Africa - both seen as existential challenges for the bloc.
"Going from an EU of 27 to an EU of 35 will create many challenges internally. We will open in Granada this large debate that will take us to a deep reform of the EU," said Sanchez.
Talks on the margins of Thursday's gathering will focus on crises between Azerbaijan and Armenia and between Serbia and Kosovo, which have flared in recent weeks amid floundering EU efforts at mediation.