MUNICH--Ukrainian President Volodymyr Zelenskyy urged Western allies Friday to quicken their military support for Ukraine, warning at a major international security conference that delays would play into Russia’s hand as the invasion approaches its first anniversary.

“There is no alternative to speed, because it’s speed that life depends on,” Zelenskyy told the Munich Security Conference in Germany.

Ukraine depends on Western weapons to thwart Russian President Vladimir Putin’s ambition to seize large areas of the country. The military aid has become a test of foreign governments’ resolve in light of increasing financial costs.

About 40 heads of state and government, as well as politicians and security experts from almost 100 countries are due to attend the three-day gathering amid fears that the fighting in Ukraine could invite a new Cold War.

In his plea for more Western weapons, Zelenskyy compared Ukraine’s struggle against the Russian invasion to the biblical fight between David and Goliath, saying his country had David’s courage but needed help getting the sling.

Zelenskyy vowed that his country would ultimately prevail over Moscow’s aggression — and even predicted that victory would happen this year. But he warned that Russia “can still destroy many lives.”

“That is why we need to hurry up,” Zelenskyy said. “We need the speed.”

Zelenskyy portrays Ukraine as defending Western values of freedom and democracy against tyranny and argues that his country needs to be properly equipped to fend off Russia’s much bigger force. Western countries have sided with him, but at times they have been slow to meet his requests.

German Chancellor Olaf Scholz, who has been one of Ukraine’s main backers, renewed pledges to help but also insisted that Kyiv’s allies must not be hasty.

“For all the pressure to act that there doubtless is, in this decisive question, care must come before rushing, cohesion before solo performances,” said Scholz, who has hesitated before taking new steps to help Ukraine.

Berlin agreed last month to deliver German-made Leopard battle tanks to Ukraine and to grant other countries permission to do the same. German officials, who faced heavy pressure to send the Leopards, have since indicated that they are disappointed other countries have not offered more armor.

Scholz urged “all who can deliver such battle tanks” to do so. He said Germany will do what it can “to make this decision easier for our partners,” for instance by training Ukrainian soldiers or helping with logistics.

The need to supply Ukraine with billions of dollars' worth of military aid has sometimes strained allied countries. After receiving Western pledges of tanks and more ammunition, Kyiv is now hoping for fighter jets, but some countries have balked at sending them.

French President Emmanuel Macron endorsed Zelenskyy’s appeal.

“We must collectively be credible,” Macron told the gathering, “because it’s the only way to make Russia come back to the negotiating table in an acceptable manner and build a sustainable peace. That is: at a time and under conditions to be chosen by Ukrainians.”

For the first time in two decades, conference organizers did not invite Russian officials to Munich. It was the latest snub as Western countries seek to isolate Russia diplomatically over the invasion that began on Feb. 24, 2022.

U.S. Vice President Kamala Harris was scheduled to address the conference on Saturday. She will lay out what’s at stake in the war, and why it matters, to bolster the case for maintaining U.S. support for Ukraine for as long as necessary, the White House said.

“We will make sure that we do everything possible within our power to strengthen Ukraine’s position on the battlefield. So that if and when there are negotiations, Ukraine will be in the strongest position in a negotiation," Harris told MSNBC in an interview that aired Friday.

She also met Friday with Macron, who thanked the U.S. for its “commitment to the security of this continent.”

Polish President Andrzej Duda said Russia's invasion must be stopped or it will not end with Ukraine.

“So there is no other option but for us to support Ukraine as much as we can,” he said.

In other developments Friday, White House National Security Council spokesman John Kirby said the U.S. intelligence community has estimated that more than 30,000 Wagner Group mercenaries have been killed or wounded while fighting in Ukraine on behalf of Russia.

About half of the Wagner dead were killed since December, Kirby said.

The U.S. believes that about 90% of those killed were convicts who Wagner pulled out of prison to join the fight, he added.