US President Donald Trump and Ukrainian President Volodymyr Zelensky shake hands during a meeting in New York on September 25, 2019, on the sidelines of the United Nations General Assembly. (Photo by SAUL LOEB / AFP)        (Photo credit should read SAUL LOEB/AFP/Getty Images)
SAUL LOEB/AFP/Getty Images
US President Donald Trump and Ukrainian President Volodymyr Zelensky shake hands during a meeting in New York on September 25, 2019, on the sidelines of the United Nations General Assembly. (Photo by SAUL LOEB / AFP) (Photo credit should read SAUL LOEB/AFP/Getty Images)
Now playing
02:01
Texts between US diplomats and Ukrainians released
Joe Manchin
CNN
Joe Manchin
Now playing
02:03
'I never thought in my life ...' Why Manchin won't walk away from bipartisanship
Gaetz speaks to members of the media outside the hearing Michael Cohen, former attorney and fixer for President Donald Trump, testifies at before the House Committee on Oversight and Reform at Rayburn House Office Building February 27, 2019 on Capitol Hill in Washington, DC. Last year Cohen was sentenced to three years in prison and ordered to pay a $50,000 fine for tax evasion, making false statements to a financial institution, unlawful excessive campaign contributions and lying to Congress as part of special counsel Robert Mueller's investigation into Russian meddling in the 2016 presidential elections.
Alex Wong/Getty Images
Gaetz speaks to members of the media outside the hearing Michael Cohen, former attorney and fixer for President Donald Trump, testifies at before the House Committee on Oversight and Reform at Rayburn House Office Building February 27, 2019 on Capitol Hill in Washington, DC. Last year Cohen was sentenced to three years in prison and ordered to pay a $50,000 fine for tax evasion, making false statements to a financial institution, unlawful excessive campaign contributions and lying to Congress as part of special counsel Robert Mueller's investigation into Russian meddling in the 2016 presidential elections.
Now playing
06:11
'Bombastic, antagonistic, unapologetic': A look at Gaetz's political career
Former House Speaker John Boehner attends a ceremony to unveil a portrait of himself on Capitol Hill, Tuesday, Nov. 19, 2019 in Washington.
Michael A. McCoy/AP
Former House Speaker John Boehner attends a ceremony to unveil a portrait of himself on Capitol Hill, Tuesday, Nov. 19, 2019 in Washington.
Now playing
02:42
Boehner says Republican colleague held 10-inch knife to his throat outside House floor
President Joe Biden, accompanied by Vice President Kamala Harris, and Attorney General Merrick Garland, speaks about gun violence prevention in the Rose Garden at the White House, Thursday, April 8, 2021, in Washington.
Andrew Harnik/AP
President Joe Biden, accompanied by Vice President Kamala Harris, and Attorney General Merrick Garland, speaks about gun violence prevention in the Rose Garden at the White House, Thursday, April 8, 2021, in Washington.
Now playing
02:05
Biden calls for ban on assault weapons
CNN
Now playing
02:22
Biden: High-speed internet is infrastructure
AFP/Getty Images
Now playing
03:24
Donald Trump breaks his silence on Matt Gaetz
CNN/WLOX
Now playing
01:43
'He says the quiet part out loud': Borger reacts to GOP election official's remark
AFP/Getty Images
Now playing
02:30
Haberman: Trump had to be talked out of defending Matt Gaetz
CNN
Now playing
03:26
Georgia's Lt. governor says elections law was a result of Trump's misinformation
Now playing
02:38
GOP lawmakers can't give examples of why states need anti-transgender sports bills
CNN
Now playing
03:04
Avlon reacts to McConnell's advice to corporations
WASHINGTON, DC - APRIL 06:  U.S. President Joe Biden delivers remarks on the state of vaccinations in the U.S. in the State Dining Room of the White House April 6, 2021 in Washington, DC. President Biden announced that states should make all adults eligible for COVID-19 vaccine by April 19.  (Photo by Alex Wong/Getty Images)
Alex Wong/Getty Images North America/Getty Images
WASHINGTON, DC - APRIL 06: U.S. President Joe Biden delivers remarks on the state of vaccinations in the U.S. in the State Dining Room of the White House April 6, 2021 in Washington, DC. President Biden announced that states should make all adults eligible for COVID-19 vaccine by April 19. (Photo by Alex Wong/Getty Images)
Now playing
01:12
'Smarten up': Biden admonishes states' restrictive voting laws
WAVE
Now playing
01:27
'It's stupid': McConnell's warning for corporate America
reality check thumb
reality check thumb
Now playing
02:48
John Avlon breaks down fraud claims among Trump donors
Now playing
06:22
Key figure in Gaetz extortion claims responds
(CNN) —  

Ukraine will review previous investigations into the owner of an energy company linked to the son of former US Vice President Joe Biden, the country’s prosecutor general announced Friday.

Ruslan Riaboshapka said his office was reviewing a number of cases opened by previous prosecutors, including probes into the owner of Burisma Holdings, a Ukrainian natural gas company that Hunter Biden once sat on the board of.

US President Donald Trump pressured Ukrainian leader Volodymyr Zelensky to investigate both Bidens during a phone call on July 25, setting off an impeachment inquiry into whether Trump abused the power of his office in order to damage a political rival.

“We are reviewing all cases opened by the previous prosecutor’s office,” Riaboshapka said when asked specifically about Burisma on Friday. “We will conduct an audit of previous cases including the one you mentioned.”

Hunter Biden sat on the board of directors at Burisma from May 2014 until April 2019. Trump has claimed, without offering proof, that Joe Biden tried to have Ukraine’s top prosecutor ousted in 2016 to stop investigations of Burisma, to benefit his son.

But the investigations did not produce any prosecutions, and there is no evidence of wrongdoing by either Biden, nor that Hunter Biden himself was ever under investigation.

Joe Biden was pushing Ukraine to fire the prosecutor general, Viktor Shokin, at the time, as were other American allies, including the International Monetary Fund and Ukrainian anti-corruption activists who said Shokin had failed to effectively investigation corruption in Ukraine.

Shokin was widely faulted for declining to bring prosecutions of elites’ corruption, and he was even accused of hindering corruption investigations. His deputy, Vitaliy Kasko, resigned in February 2016, alleging that Shokin’s office was itself corrupt, and Ukraine’s legislature voted to fire Shokin the following month.

The announcement by the current prosecutor general, Riaboshapka, on Friday came during a news conference in which he detailed reforms to the country’s prosecutor service, including the creation of a new department for high profile cases.

“We are fighting against the old system,” he said. “Prosecutors should be honest and uphold the rule of law in Ukraine rather than work towards business or political requests.”

This story has been updated to correct the nature and focus of investigations Ukrainian prosecutors are reviewing.