MUNICH (AP) — U.S. Vice President Kamala Harris warned Russia on Saturday that it will face “unprecedented” financial costs if it invades Ukraine and predicted that such an attack would draw European allies closer to the United States.

Harris spoke at the annual Munich Security Conference in Germany the day after President Joe Biden said he’s “convinced” that Russian President Vladimir Putin has made the decision to invade the neighboring country.

“Let me be clear, I can say with absolute certainty: If Russia further invades Ukraine, the United States, together with our allies and partners, will impose significant, and unprecedented economic costs,” Harris said.

The vice president aimed to make the case to a largely European audience that the West has “strength through unity” and that an invasion would likely lead to an even bigger NATO footprint on Russia’s doorsteps.

Russia annexed Ukraine’s Crimea Peninsula in 2014, and pro-Russia separatists have been fighting Ukrainian forces in the country’s east for almost eight years. The U.S. and the European Union previously sanctioned Russia over its seizure of Crimea.

Western fears of an invasion have escalated in recent months as Russia amassed more than 150,000 troops near Ukraine’s borders.

Harris said the Biden administration, along with its allies, had sought to engage with Moscow in good faith to find a diplomatic resolution but was not met by the Kremlin in good faith.

“Russia continues to say it is ready to talk while at the same time it narrows the avenues for diplomacy,” Harris said. “Their actions simply do not match their words.”

Harris credited European allies for speaking with a largely unified voice as the latest Ukraine crisis has unfolded. The vice president said Republicans and Democrats in Washington — who rarely agree on many major issues — have largely reached the same page on the necessity of confronting Putin.

“We came together and are now speaking with a unified voice,” Harris said.

Harris on Friday declared “our greatest strength is our unity” as she met with the leaders of Estonia, Latvia and Lithuania on the sidelines of the conference. The Baltic countries have requested the U.S. increase its troop presence on the eastern edge of NATO.

The White House has not yet said whether it will fulfill those requests, but Harris suggested in her comments that an invasion would lead to a bolstered American presence.

“We will further reinforce our NATO allies on the eastern flank,” Harris said.

As the brewing crisis gets more complicated by the day, Biden and other administration officials have offered increasingly dire warnings that the window for diplomacy is narrow.

Biden told reporters Friday that he believes Putin has decided to invade in the coming days, taking military action that could go far beyond the disputed Donbas region in eastern Ukraine and include the capital of Kyiv.

As Harris makes a late-inning push to Putin to pull back, she aimed to hit hard on the argument that the U.S. will emerge stronger from a conflict while Russia will emerge weaker.

The vice president was scheduled to meet after her speech on Saturday with German Chancellor Olaf Scholz and Ukrainian President Volodymyr Zelenskyy.

Biden demurred when asked Friday about the wisdom of Zelenskyy leaving Ukraine to attend the Munich conference at a moment when the Biden administration warns an invasion could be coming any day.

“That’s a judgment for him to make,” Biden said of Zelenskyy.

The Munich gathering has been used in recent years by both U.S. and Russian leaders to deliver pivotal messages before an important audience.

Then-Vice President Mike Pence in 2019 pitched President Donald Trump’s “America First” worldview, receiving a tepid response from the mostly European crowd. Biden has addressed the conference as a private citizen, senator, vice president, and president.

At last year’s conference, held virtually due to the coronavirus pandemic, a then-new President Biden declared “America’s back” in an address that touched on economic and security concerns driven by adversaries Russia and China.

Fifteen years ago, Putin used his own Munich appearance to deliver a broadside against NATO, accusing the alliance of putting “its frontline forces on our borders.” It’s a message that Putin continues to press as he demands the U.S. and other NATO nations guarantee that Ukraine — long aspiring to be included in the alliance — will never be given entry.

Harris’ opportunity to demonstrate her policy chops abroad hasn’t been lost on GOP detractors.

“Putin is a bully who responds to strength. Sending VP Harris to Europe for meetings and speeches will only amuse him,” tweeted Nikki Haley, who served as Trump’s U.N. ambassador and is a potential 2024 presidential contender.

But Harris in her remarks was laser-focused on her assignment to rally allies.

“Our strength must not be underestimated. It lies in our unity,” she said. “And as we have always shown, it takes a lot more strength to build something up than it takes to tear something down.”