Ukrainian President Volodymyr Zelenskyy's surprise trip to Washington and address to Congress comes as pressure mounts from House Republicans to audit or even cut aid to Ukraine as they prepare to take majority control just days away in January.
Some conservative House Republicans have made it clear they would even oppose any additional funding as Congress votes on a must-pass $1.7 trillion government funding bill that includes $45 billion in aid to Ukraine.
MORE: Ukraine's Zelenskyy in Washington live updates: Arrives at White House in dramatic visitWhen asked how much of Zelenskyy's visit is about President Joe Biden pressuring the incoming GOP-controlled House to keep U.S. aid for Ukraine flowing, a senior administration official told ABC News that the visit was not about politics.
"This isn't about sending a message to a particular political party, this is about sending a message to Putin and sending a message to the world that America will be there for Ukraine for as long as it takes," the official said.
Current House Minority Leader Kevin McCarthy -- needing to win over conservatives to back his bid for speaker -- has signaled he could oppose more funding.
He has warned that Republicans will not write a "blank check" for Ukraine when they assume the majority.
"I think people are gonna be sitting in a recession and they're not going to write a blank check to Ukraine," McCarthy told Punchbowl News. "They just won't do it. … It's not a free blank check."
McCarthy later doubled down on his comments, telling CNN that he supported Ukraine but didn't close the door in opposing funding. "I am very supportive of Ukraine. It means no blank checks for anything ... I think there has to be accountability brought forth," he said.
He confirmed to ABC News on Wednesday that he would attend Zelenskyy's address to lawmakers.
Some of most conservative House Republicans, including GOP Reps. Marjorie Taylor Greene, Matt Gaetz, Andrew Clyde, Barry Moore, Thomas Massie, and incoming Florida Rep. Cory Mills, have claimed the funding shelled out for Ukraine should be spent domestically instead.
"American taxpayers are literally paying to prop up many countries all over the world in foreign aid, but America is virtually crumbling before our eyes," Rep. Marjorie Taylor Greene argued in a series of tweets on Wednesday after Zelenskyy's visit was announced.
"Of course the shadow president has to come to Congress and explain why he needs billions of American's taxpayer dollars for the 51st state, Ukraine.This is absurd. Put America First!!!" She tweeted.
At a Nov. 17 news conference, the group introduced resolution, later defeated, urging the Biden administration to provide a full audit of how U.S. aid to Ukraine is being spent.
"I will note vote for one more dollar to Ukraine," Gaetz said.
Meanwhile, more moderate Republican Reps. Michael McCaul, R-Texas, and Mike Turner, R-Ohio, last month on ABC News' "This Week" while backing McCarthy's comments about no "blank check," also insisted that the incoming House Republican majority would continue to support funding and arming Ukraine.
MORE: Top House Republicans support more aid for Ukraine but want 'accountability'At the same time, Senate Minority Leader Mitch McConnell, R-Ky., has made the case for more military aid for Ukraine -- arguing for it on Wednesday just before Zelenskyy arrived.
"Continuing our support for Ukraine is morally right, but its not only that, its also a direct investment in cold hard American interest," McConnell said.
"The reason that a big bipartisan majority of the American people and a big bipartisan majority in Congress support continuing to assist Ukraine is not primarily about inspiring speeches or desire to engage in philanthropy," McConnell said on the Senate floor.
"The most basic reasons for continuing to help Ukraine degrade and defeat the Russian invaders are cold, hard, practical, American interests," he continued. "Helping equip our friends in eastern Europe defeat this world is also a direct investment in reducing Putin's future capabilities to menace America, threaten our allies and contest our core interests."
Latest polling found a near-even split of American opinion on Biden's handling of the response to Russia's invasion of Ukraine. Forty-five percent approve while 46% disapprove of his actions, according to a Dec. 14 Quinnipiac Poll.
Democrats have called out House Republicans for their growing skepticism about sending more aid to Kyiv..
"I hope that Donald Trump's friendship with Putin is not motivating Republicans to turn a blind eye to Ukraine's suffering and desperate need for help," Senate Majority leader Chuck Schumer, D-N.Y., said on Wednesday morning.
"Because the so-called friendship between Putin and Trump was a sour relationship that was deeply damaging to our country and to the international order."
ABC News' Allie Pecorin, Justin Gomez, and Tal Axelrod contributed to this report.