NEW YORK – Until last week, Volodymyr Zelenskiy was a little-known, bit player on the world stage – a former a comedian who played the role of an accidental president on a popular Ukrainian TV show.

Now, Zelenskiy really is president – and the Ukrainian leader is at the center of a diplomatic and political firestorm that has prompted impeachment proceedings against his American counterpart, Donald Trump.

Trump and Zelenskiy are set to meet Wednesday on the sidelines of the United Nation’s General Assembly’s meetings in New York, setting up a high-stakes spectacle with implications for the political future of both men. Trump and Zelenskiy are both likely to face reporters' questions before their talk.

The meeting will reduce the enormity of the widening scandal – and the historic decision by House Speaker Nancy Pelosi on Tuesday to open a formal impeachment inquiry – to a small conference room in a Manhattan hotel, a few minutes of small talk by the leaders followed by sharp questioning from reporters.

It will also thrust a little known world leader to the fore.

Zelenskiy is used to the hot lights of show business, but “this is a stage unlike any he’s ever been on,” said Heather Conley, director of the Europe program at the Center for Strategic and International Studies, a Washington-based foreign policy think tank.

“This whole controversy puts him in an incredibly difficult position,” Conley said.

Zelenskiy won a surprise victory in April, defeating Ukraine’s incumbent president, Petro Poroshenko, in a landslide. He was sworn into office in May, inheriting a troubled economy, a raging conflict with Russia and endemic corruption.

“He’s completely a neophyte to politics,” said Ian Bremmer, a political analyst who leads the Eurasia Group, a global consulting firm. “He’s known as an entertainer, as a comedian portraying the Ukrainian president in a popular local show.”

His election in April was “not quite as surprising and out-of-the blue as Trump being elected president in the U.S.,” Bremmer said, “but it’s close.”

Like Trump, Zelenskiy campaigned as an outsider running against the political establishment. He promised to clean up corruption in Ukraine and ease tensions with Russia.

But soon after taking office, Zelenskiy ran into an unanticipated problem with his country's most important ally, the United States. Trump had decided to freeze nearly $400 million in military aid to Ukraine, which Congress had approved to help the Eastern European nation counter Russian aggression.

Trump’s decision to temporarily block that assistance is now at the center of allegations that he abused his power to pressure Zelenskiy to open an investigation into former Vice President Joe Biden and Biden’s son, Hunter, who had business dealings in Ukraine.

Trump has admitted that he raised the Bidens and corruption in a July 25 phone call with Zelenskiy, but he defended that conversation as “perfect" and appropriate. Most Republicans have either sidestepped questions about the controversy or accused Democrats of blowing it out of proportion.

"What I really see happening is that Democrats are winding up the outrage machine again," said Sen. John Barrasso, the third highest-ranking Republican in the Senate, adding it's all about "beating the impeachment drum."

Trump and his personal attorney Rudy Giuliani have pushed claims for months that Biden, in 2016 when he was as vice president, sought the removal of Ukraine’s then-prosecutor general Viktor Shokin to stop an investigation into Burisma Group, a Ukrainian energy company where his son Hunter served on the board of directors. European diplomats and the U.S. State Department also pressed for Shokin's ouster, saying he was not aggressive enough in fighting corruption.

Trump also confirmed on Tuesdaythat he sought to block the aid to Ukraine, telling reporters he wanted other countries to step up their support – one of several explanations he and his staff have offered as the scandal around his conversations with Zelenskiy mushroomed.

"Germany, France, other countries should put up money, and that has been my complaint from the beginning," Trump said before delivering remarksto the United Nations General Assembly.

Sen. Chris Murphy, D-Conn., said the stalled military aid was the “first question” Zelenskiy asked him when he visited Ukraine earlier this month.

“The suspension of security aid, to him, was not just about the practical impact on his military but also the message it was sending to Russia about his partners getting cold feet,” Murphy told USA TODAY.

It’s a signal of America’s “rock solid support for Ukraine,” Murphy added, “and to the extent that (Russian President Vladimir) Putin chooses not to ramp up military activity along the line of contact, that’s in part because he sees that the United States is committed to supporting the Ukrainian military.”

Murphy said Zelenskiy asked him and Sen. Ron Johnson, R-Wis., who was also on the official congressional trip, about getting a meeting with Trump to press his case for the release of the aid.

Trump released the military aid earlier this month under bipartisan pressure from Congress. And Zelenskiy will get his meeting with Trump on Wednesday, although under much different circumstances than either man anticipated.

Now, Murphy and other Democrats are accusing Trump of using the foreign assistance as leverage to get dirt on Biden, who is running for the Democratic presidential nomination and saying his actions amount to an impeachable offense.

“The president seems very transparent about the fact that he’s trying to corrupt the Ukrainian leader into supporting his political objectives,” Murphy said. “It wouldn’t surprise me if the president walks into that meeting and starts browbeating Zelenskiy about opening up a politically motivated investigation of” the Bidens.

Conley said Zelenskiy will have to walk a fine line on Wednesday. He doesn’t want to further alienate Trump because he needs U.S. support as he tries to keep Russia at bay and rebuild Ukraine’s economy, not to mention rooting out decades of Ukrainian corruption.

“The world is going to be watching this meeting and for any sign or word or language” from Zelenskiy, she said. “I think so far what you’ve seen right now is restraint. They are trying to not get pulled into this either way.”

Bremmer said Zelenskiy appears to be a straight shooter, and his refusal to bow to Trump’s pressure in the July 25 call shows that. But he fears that Trump will “double down” on his accusations of Ukrainian corruption and damage U.S.-Ukraine relations in the process.

“All of this is going to make Trump extremely defensive and very aggressive,” he said.

It’s possible that Trump will just train his ire on Biden and say that Zelenskiy “is a good guy,” Bremmer said, but “the pressure of this story is going to be massive.”

Contributing: David Jackson, Christal Hayes