A Ukrainian lawmaker who met with Rudolph W. Giuliani late last year released recordings of private phone calls several years ago between Vice President Joe Biden and Petro Poroshenko, then Ukraine’s president, in a new broadside against the presumptive Democratic nominee for U.S. president that has raised questions about foreign interference in the 2020 election.

Andriy Derkach, an independent member of Ukraine’s parliament who previously aligned with a pro-Russian faction, said at a news conference in Kyiv on Tuesday that he had received the tapes — which consist of edited fragments of phone conversations Biden and Poroshenko had while still in office — from “investigative journalists.” He alleged they were made by Poroshenko.

Derkach has past links to Russian intelligence. He attended the Dzerzhinsky Higher School of the KGB in Moscow. His father served as a KGB officer for decades before becoming head of independent Ukraine’s intelligence service in the late 1990s. His father was fired from that post amid a scandal over a Ukrainian journalist who was kidnapped and murdered.

The recordings played at the news conference Tuesday shed relatively little new light on Biden’s actions in Ukraine, which were at the center of President Trump’s impeachment last year. They show that Biden, as he has previously said publicly, linked loan guarantees for Ukraine to the ouster of the country’s prosecutor general in 2015. But Derkach used the new clips to make an array of accusations not proven by the tapes.

Donald Trump Jr., the president’s son, posted one of the recordings on Twitter hours later and implied impropriety by Biden. “Yikes!!!! This is not a ‘perfect conversation,’ ” Trump Jr. wrote.

The events have echoes of the 2016 presidential election, when Russian operatives hacked and released emails from the campaign manager of Democratic nominee Hillary Clinton and officials at the Democratic National Committee, in what U.S. intelligence agencies later concluded was a Moscow-directed operation designed to boost Trump.

Trump’s allies, including Giuliani, have argued that Ukraine intervened in that election on Clinton’s behalf, in part by targeting Trump’s campaign chairman, Paul Manafort. The country’s anti-corruption bureau released entries from a black ledger that allegedly showed $12 million in cash payments from its Russia-leaning political party to Manafort during the years in which he worked as a political consultant in Ukraine. Manafort said the document was falsified, but the revelations prompted him to resign from the Trump campaign in the summer of 2016.

Nearly four years later, Trump’s eldest son is blasting leaked information of unknown provenance from a Ukrainian lawmaker about his father’s rival in the 2020 election. Trump Jr.’s tweet linked to a YouTube page with a recording that was also packaged with English subtitles.

Giuliani, who serves as Trump’s personal attorney, met Derkach during a trip to Kyiv in December.

Giuliani did not answer questions sent by text message asking whether he knew about the recordings before their release or worked with Derkach to ensure they became public, instead saying attention should be focused on what he claimed was the Biden family’s sale of his vice-presidential office.

“Just the tip of iceberg,” he wrote in a text.

The tapes released in Kyiv offered no evidence to back Giuliani’s long-standing accusation that Biden pushed for the prosecutor general’s ouster to help his son. At the time, Hunter Biden was earning between $50,000 and $100,000 a month on the board of the Ukrainian gas company Burisma, whose owner, a former government minister, was under investigation in Ukraine. Still, the tapes gave Trump’s allies a chance to recycle that allegation closer to the 2020 election.

The Biden campaign viewed the release of the tapes as a continuation of a long-standing Russian effort to hurt the former vice president, pointing to the role that RT, the Russian state-controlled news network, played in promoting the tapes and noting Derkach’s ties to Russian interests.

“They heavily edited this, and it’s still a nothingburger that landed with a thud,” Biden spokesman Andrew Bates said.

As with Trump’s efforts regarding Ukraine last year, which included pressuring Ukrainian President Volodymyr Zelensky to investigate Biden and his son, Biden’s circle reiterated how consistent the conversations on the tapes were with official U.S. and European policy at the time and with what Biden and Poroshenko have both said publicly since.

The release of the tape fragments by Derkach is a Russian provocation designed to tarnish Ukraine and drag the country artificially into the U.S. presidential campaign, Poroshenko’s political party, European Solidarity, said in a statement to Channel 5, the Ukrainian television network he owns. The party said it was an attempt to ruin the support Ukraine enjoys in the United States.

The clips released in Kyiv consisted of conversations that Biden had as vice president with Poroshenko, primarily about domestic Ukrainian political issues. At the time, Biden was the face of U.S. policy toward Ukraine, demanding as a matter of policy that the government make reforms to end corruption if it wanted to continue to receive billions of dollars in Western aid and loan guarantees.

In late 2015, Biden led a coalition of Western nations and U.S. officials who sought the ouster of Ukrainian Prosecutor General Viktor Shokin after a scandal erupted under his watch in which prosecutors were found with bags of diamonds and stashes of cash. Shokin also clashed with two young prosecutors who Western officials hoped would clean up what has long been a corrupt office.

The vice president publicly pushed for reform of the prosecutor general’s office at the time. Biden later said that he told Poroshenko that Ukraine would not receive $1 billion in loan guarantees unless Shokin was removed and the prosecutor general’s office was reformed. Much of that is recounted on the tapes.

In one clip, Biden congratulates Poroshenko on installing a new prosecutor general.

“It’s going to be critical for him to work quickly to repair the damage that Shokin did,” Biden says. “And I’m a man of my word. And now that the new prosecutor general is in place, we’re ready to move forward to signing that new $1 billion loan guarantee.”

At no point in the clips released Tuesday does Biden mention Burisma or his son. Biden has denied discussing the gas company with his son, and his advisers have emphasized that he was pushing for Shokin’s ouster as a matter of U.S. foreign policy toward Ukraine, which called for anti-corruption reforms.

In one call, Poroshenko reported to Biden that he had met with Shokin and asked for his resignation and that Shokin had, an hour before the call, complied and written a letter resigning from his post. Poroshenko described the move as the “second step of keeping my promises.”

“Great,” Biden replied. “I agree.”

In the recordings, Poroshenko also appeared to seek Biden’s approval before appointing Yuri Lutsenko to replace Shokin, noting that if Biden was opposed to a “politically motivated figure” like Lutsenko taking on the role, he could rethink the move.

Biden replied that he would “huddle” with his team and “talk over what you and I just talked about.” It is unclear whether Biden was referring to Poroshenko’s comments about Lutsenko or other items they discussed on the call.

Josh Dawsey and Michael Scherer contributed to this report.