Russia has started to make steady progress against Ukraine as Kyiv's forces face dwindling ammunition supplies, much to Ukrainian President Volodymyr Zelenskyy’s frustration. 

"There can be no question, Ukraine could be quickly overwhelmed by both men and arms by odds as great as 10 to 1 within weeks without additional U.S. assistance," Kenneth Braithwaite, a former ambassador and former Navy secretary during the Trump administration, told Fox News Digital. 

"This is a critical juncture in the war and time is of the essence for Congress to act on a comprehensive package," Braithwaite said. "The fact remains that Putin’s only chance to win in Ukraine is if the West loses our resolve." 

"Therefore, the math is pretty easy, we can pay now or we pay later – and if we pay later, the costs will be astronomically higher for our security and economic interests," he added. "In our Navy we ‘Don’t Give Up The Ship’: That’s never been more true than now when it comes to our nation's support for Ukraine."

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Zelenskyy Putin

Zelenskyy and Putin

Ukraine has made some gains over the past year by shifting their strategy from broad land offensives to focused drone attacks, including some assassination attempts, but continues to seek progress against the staunch and dug-in Russian defenses.

"All of our European neighbors and other partners see Ukraine's critical need for air defense systems," Zelenskyy wrote in a post on social media platform X. "Right now, with our ability to overcome Russian terror, the world can demonstrate that all terror is treated equally as a crime."

Ukraine military assessment

President Volodymyr Zelenskyy inspects bunkers, firing ranges, armored personnel carrier trenches during a visit to the Chernihiv Oblast in Ukraine on April 5, 2024. (Ukrainian Presidency/Handout/Anadolu via Getty Images)

"However, if Russia is allowed to continue doing so, if Russian missiles and 'Shahed' drones continue to strike not only Ukraine but also the resolve of our allies, this will amount to a global license for terror," he added. "We need air defense systems and other defense assistance, not just turning a blind eye and having lengthy discussions."

"Let’s remember that Russian forces are getting help from countries like Iran and North Korea. Ukrainian soldiers are having to ration their bullets and supplies. They’re fighting valiantly and will succeed if we simply give them additional resources," Ambassador Mark Green, president, director and CEO of the Wilson Center told Fox News Digital. 

In an interview with German outlet BILD, Zelenskyy acknowledged that Ukraine has managed to continue to produce many drones domestically, but other systems, including air defense systems, long-range missiles and other types of artillery, remain in high demand and low supply. 

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Zelenskyy said Kharkiv could face a major offensive in the summer, saying Russian President Vladimir Putin "naturally wanted to take Kharkiv because it is a big symbol for him," but insisting that "Ukraine is ready to thwart Russia’s plans to conquer: We do everything we can to prevent this from happening."

He also warned that Russia’s attacks on Ukrainian energy infrastructure have proven successful and continue to have a "big impact" on the war as they "cause great pain to the population and cities." 

Ukraine town destroyed

A multistory residential building and stores were heavily damaged by a Russian aerial bombing on April 10, 2024, in Kostiantynivka, Donetsk Oblast, Ukraine. (Andriy Reznikov/Suspilne Ukraine/JSC "UA:PBC"/Global Images Ukraine via Getty Images)

"He will destroy everything," Zelenskyy said, referring to Putin. "He will kill a lot of people… most people won’t run away, so he will kill many of them. What will it look like? There will be a lot of blood. There will be many victims, many losses. We speak of hundreds of thousands." 

The U.S. has met internal resistance over continued and seemingly unending funding for the Ukrainians against Russia: The Senate passed a $95 billion aid package that includes support for Ukraine, Israel and Taiwan, but the House has yet to schedule a vote as some noted Republican holdouts in both chambers seek to derail efforts to pass it. 

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Rep. Eli Crane, R-Ariz., told Fox News Digital that Ukraine appears to be "another forever war that will bankrupt future generations – all while disregarding our own security as our southern border remains open." 

House Speaker Mike Johnson, R-La., has revealed his intent to take action on the aid package once lawmakers return to Washington next week, including a proposal to liquidate seized Russian assets and re-purpose those funds as assistance for Ukraine. Senate Minority Leader Mitch McConnel, R-Ky., declared that he’s committed to opposing Russia’s invasion for the remainder of his term. 

Ukraine invasion residents

Volunteers deliver water to residents who have returned to the village of Dovhenke, Ukraine on April 5, 2024. (Wojciech Grzedzinski/Anadolu via Getty Images)

President Biden urged the House to pass the aid package, arguing that "the majority of Democrats and Republicans" have shown "overwhelming" support for Ukraine: "There should be a vote now," Biden said during a press briefing on Wednesday. 

U.S. Secretary of Defense Lloyd Austin told lawmakers earlier this week that aid for Ukraine is vital to national and global security.

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"Our security in these turbulent times relies on American strength of purpose," Austin said. He argued that Putin "is betting that the United States will falter and abandon our friends and leave Ukraine in mortal danger. If the Kremlin prevails in Ukraine, it will embolden would-be aggressors around the globe and the United States would be far less secure if Putin got his way in Ukraine."

"If America walked away, we would put the free world in peril and risk unimaginable costs and dangers, and we know that China and others are watching and learning from what Putin does and how we respond," he added.

Kyiv NATO bilateral deal

President Volodymyr Zelensky meets with Lithuania's President Gitanas Nauseda in Vilnius, on April 11, 2024, as the Ukrainian leader seeks more military aid from Western nations. (Petras Malukas/AFP via Getty Images)

The lagging U.S. support has frustrated Zelenskyy, forcing him to seek aid from other sources: Zelenskyy traveled to NATO ally Lithuania to participate in a regional security summit on Thursday, where he continued to press the broader threat Putin poses for NATO and Europe. 

The Ukrainian president said Russian "evil" is a threat "to every nation bordering Russia and to everyone who values international law," Al Jazeera reported. He secured a 10-year bilateral security agreement with Latvia, which Zelenskyy proclaimed "envisages" the support Ukraine needs. 

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Bakmut fighting

Ukrainian soldiers fire a cannon near Bakhmut, an eastern city where fierce battles against Russian forces have been taking place, in the Donetsk region, Ukraine, May 15, 2023. For months, Western allies have shipped billions of dollars worth of weapons systems and ammunition to Ukraine with an urgency to get the supplies to Kyiv in time for an anticipated spring counteroffensive. Now summer is just weeks away. While Russia and Ukraine are focused on an intense battle for Bakhmut, the Ukrainian spring offensive has yet to begin. (AP Photo/Libkos)

Rebekah Koffler, a strategic military intelligence analyst and the author of "Putin's Playbook," told Fox News Digital that the seeming shift in momentum is unsurprising, claiming that Ukraine’s victory was "unattainable from the very start" and that the war become a "tragedy of epic proportions" as the U.S. and Europeans used Ukraine "effectively… as human shields to protect the Europeans." 

"Thousands of Ukrainian men are being thrown as meat into Putin’s meat grinder, in order to weaken the Russian military, so that Europeans can feel safer," Koffler said. "And hence, the country of Ukraine is being de-populated and devastated by Putin, who would have never accepted the perceived risk of having Ukraine being part of NATO, an adversarial alliance close to Russia’s borders."

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Koffler argued that continuing to fund Ukraine remained untenable as "U.S. resources are not limitless, the patience of U.S. taxpayers isn’t either."

"The writing for Ukraine is on the wall, and yet the Biden administration, the Pentagon and Western defense establishments are pretending not to see it. It’s not convenient for them to see it," she said. 

Fox News Digital's Julia Johnson and Elizabeth Elkind contributed to this report.