In his fourth and likely final trip to Ukraine ahead of the U.S. election next month, Secretary of Defense Lloyd Austin championed Ukraine’s efforts to repel Russian President Vladimir Putin’s deadly years-long assault but warned there is "no silver bullet" to end the war. 

"There is no silver bullet. No single capability will turn the tide. No one system will end Putin’s assault," Austin said, speaking from Ukraine’s Diplomatic Academy in Kyiv.

"What matters is the way that Ukraine fights back," he added. "What matters is the combined effects of your military capabilities, and what matters is staying focused on what works."

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Austin applauded the bilateral efforts by the U.S. and its international allies to aid Ukraine in its fight against the Kremlin and warned Ukraine’s security is a matter of not only European security, but the U.S.’s.

International concern has mounted in recent months as the U.S. stares down a presidential election in just over two weeks and questions remain over whether a second Donald Trump White House would continue to back Kyiv should he win.

In a continued show of solidarity, Austin announced another $400 million arms package for Ukraine, and argued the cost of aiding Kyiv is less costly than abandoning it to Putin.

"Consider the price of American retreat. In the face of aggression, the price of principle is always dwarfed by the cost of capitulation," Austin said. "We face a hinge in history.

"We can continue to insist that cross-border invasion is the cardinal sin of world politics, and we can continue to stand firm against Putin's aggression. Or we can let Putin have his way, and we can condemn our children and grandchildren to live in a far bloodier and more dangerous world," he continued.

"If Ukraine falls under Putin’s boot, all of Europe will fall under Putin’s shadow."

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Austin argued Putin has yet to achieve a single objective of his "special military operation" when he invaded Ukraine nearly a thousand days ago, including his inability to take Kyiv or force Ukrainian President Volodymyr Zelenskyy to step aside. 

The secretary pointed to the more than 600,000 casualties Russia has incurred since February 2022, and the 11,000 Ukrainian civilians, including 600 children, that have been killed, according to figures by the United Nations.

Zelenskyy in a message posted to X, thanked Austin for his visit and the defense package, and said the pair discussed not only defense priorities and winterizing against Russia’s promised assault on Ukraine’s energy infrastructure, but also "the expansion of long-range weapon use against Russian military targets."

The Ukrainian president has long pushed the U.S. to enable it to use long-range weapons to hit military sites deeper in Russia in a move to stop its deadly aerial assaults on Ukrainian cities. 

The U.S. has remained largely opposed to this tactic, and Austin did not mention any long-range strike capabilities during his address Monday. 

Austin pledged to continue driving international efforts to back Ukraine with the military aid it needs to battle Russian troops on its eastern front.

"When a dictator puts his imperial fantasies ahead of the rights of a free people, the whole international system feels the outrage," he said. "And so that’s why nations of goodwill from every corner of the planet have risen to Ukraine's defense.

"And that's why the United States and our allies and partners have proudly become the arsenal of Ukrainian democracy," Austin added.