KIEV (Reuters) - Ukraine has unwittingly become embroiled in a political battle in Washington between U.S. President Donald Trump and congressional Democrats who could announce formal impeachment charges against him within weeks.

Democrats launched an inquiry in September into allegations Trump abused his power to pressure Ukraine President Volodymyr Zelenskiy to investigate former Vice President Joe Biden, a Democratic possible rival in the 2020 presidential race.

Trump calls the inquiry a partisan “witch hunt” and neither he nor his lawyers have agreed to appear in an inquiry hearing on Wednesday.

WHAT DOES TRUMP WANT FROM UKRAINE?

In a July 25 phone call, Trump pressed Zelenskiy to investigate an allegation that Biden, while in office, muscled the Ukrainian authorities to fire a top prosecutor to shut down a probe that could implicate his son Hunter.

Zelenskiy agreed to do so, according to a partial transcript that was released by the White House.

On the same call, Trump brought up a conspiracy theory that a hacked Democratic National Committee computer server was in Ukraine.

Democrats are also investigating whether Trump abused his powers by temporarily freezing $391 million in security aid to pressure Zelenskiy. Trump denies doing so.

HOW HAS UKRAINE REACTED?

Zelenskiy denies being pressured by Trump and says he was unaware Trump had frozen aid at the time of their call. Zelenskiy’s administration insists it does not want to take sides or interfere in next year’s U.S. election.

Ukraine is acutely aware it relies on bipartisan support as well as military aid from Washington as Kiev battles Russian-backed separatists in the eastern Donbass region in a conflict that has killed more than 13,000 people.

Persistently questioned about the impeachment inquiry by journalists, Zelenskiy said last month that Ukrainians were tired of the issue.

In an interview, Zelenskiy denied speaking to Trump about a “quid pro quo”.

“I don’t want us to look like beggars. But you have to understand. We’re at war. If you’re our strategic partner, then you can’t go blocking anything for us,” he was quoted by Time magazine as saying.

WHAT ARE THE ACCUSATIONS AGAINST BIDEN?

By his own account, Joe Biden pressed the Ukrainian authorities to fire Prosecutor General Viktor Shokin in 2016, threatening to withhold $1 billion in loan guarantees if Kiev failed to comply.

Giuliani alleged Biden did so because Shokin was investigating the activities of Biden’s son Hunter, who sat on the board of a Ukrainian gas company called Burisma.

Trump and his aides have presented no evidence of corruption by the Bidens in Ukraine. Hunter Biden denies any wrongdoing during his work for Burisma. Joe Biden denies trying to protect his son, and says pressure to fire Shokin was being applied widely by European governments at the time because of concern over corruption.

WHAT IS THE STATUS OF THE UKRAINIAN INVESTIGATIONS?

After Zelenskiy took office this year, a new prosecutor general launched a wide-ranging audit of criminal cases. Thirteen of them relate to Burisma founder Mykola Zlochevsky, a multimillionaire former minister.

The allegations concern tax violations, money laundering and licenses given to Burisma during the period where Zlochevsky was in government. Zlochevsky has not commented and his whereabouts are unknown to the Ukrainian authorities.

The prosecutor said in October he was not aware of any evidence of wrongdoing by Hunter Biden, who was on the board of Burisma between 2014-2019.

WHAT ELSE DOES TRUMP’S CAMP SAY ABOUT UKRAINE?

Giuliani alleges some Ukrainian officials conspired to help Trump’s Democratic challenger Hillary Clinton in 2016 by leaking information damaging to Trump’s then-campaign chairman, Paul Manafort.

Manafort, a long-time Republican political consultant who is now serving a prison sentence after being convicted of fraud and witness tampering, had worked in Ukraine for a previous Russia-friendly president, Viktor Yanukovich.

Giuliani and other Trump allies say Ukrainians forged a record of millions of dollars in payments -- known as the “black ledger” -- to Manafort from Yanukovich’s associates.

Separately, some right-wing websites have said that the cyber security firm CrowdStrike falsely accused Russia of hacking Democratic Party organizations and then stashed hacked email servers in Ukraine as part of a cover-up. CrowdStrike denies that.

Trump referenced that theory during his call with Zelenskiy.

WHAT ELSE DID GIULIANI DO IN UKRAINE?

Current and former U.S. officials have testified Giuliani carried out a shadow foreign policy in Ukraine, and led efforts to get Zelenskiy to announce investigations into Burisma and alleged Ukrainian interference in the 2016 U.S. election.

Text messages between Giuliani and U.S. diplomats show pressure was exerted on Zelenskiy. The U.S. ambassador to the European Union, Gordon Sondland, testified that Trump largely delegated Ukraine policy to Giuliani.

Giuliani says he met current and former Ukrainian prosecutors as part of his investigations into the Bidens and the 2016 election but played down his role in liaising with U.S. diplomats and Ukrainian officials.