The United States encouraged Ukraine to conduct an investigation linked to Joe Biden’s family in return for a high-profile visit to Washington with President Donald Trump and transfer USD 250 million in financial support to strengthen security. This is evidenced by correspondence between recently resigned U.S Special Representative for Ukraine Kurt Volker, U.S Ambassador to the European Union Gordon Sondland, U.S Charge d'Affaires in Ukraine William Taylor, and Zelenskyy's aide Andrii Yermak, which was obtained by the U.S House of Representatives’ committees on foreign affairs, oversight and reform, and intelligence and published by the Associated Press, Ukrainian News Agency reports. According to the documents, a telephone conversation was organized between Yermak and Trump's lawyer Rudy Giuliani in July. “Most important is for Zelenskyy to say that he will help investigation and address any specific personnel issues if there are any,” Volker wrote. In this context, Taylor noted that, the Ukrainian National Security and Defense Council’s former secretary Oleksandr Danyliuk made the point that "Zelenskyy is sensitive about Ukraine being taken seriously, not merely as an instrument in Washington’s domestic, reelection politics." Before the telephone conversation between Zelenskyy and Trump, Volker warned Yermak that he had heard from the White House "assuming [Zelenskyy] convinces Trump he will investigate, get to the bottom of what happened in 2016, we will nail down date for visit to Washington." After the telephone conversation between the presidents took place, Yermak told Volker that Trump suggested that Zelenskyy choose any convenient date in September for his visit to Washington, and he chose September 20-22. According to the correspondence, the American side expected Zelenskyy to make a public statement and Volker said he wanted to "make sure I advise correctly as to what he should be saying." However, Yermak pressed Volker for a date for the White House visit before committing to a statement. "Once we have a date, we will call for a press briefing, announcing upcoming visit and outlining vision for the reboot of US-Ukraine relationship, including, among other things, Burisma and election meddling investigations," Yermak wrote in a message to Volker. The text of the proposed Zelenskyy statement was agreed between Volker and Sondland. However, Yermak informed Volker on August 28 that Trump had frozen the transfer of military assistance to Ukraine. Trump later canceled his visit to Poland, where his brief meeting with Zelenskyy was to take place. Taylor asked his colleagues, "Are we now saying that security assistance and White House meeting are conditioned on investigations?" “The nightmare is they give the interview and don’t get the assistance. The Russians love it. The message to the Ukrainians (and Russians) we send with the decision on security assistance is key. With the hold, we have already shaken their faith in us. Thus my nightmare scenario. I think it is crazy to withhold security assistance for help with a political campaign," Taylor wrote. Sondland replied that Taylor was misinterpreting Trump's intentions and that he simply wanted to make sure that Zelenskyy would fulfill his promises of transparency and reform. The document ended with this message dated September 9. As Ukrainian News Agency earlier reported, Trump released the transcript of his July 25 telephone conversation with Zelenskyy on September 25, in which he asked Zelenskyy to investigate the closure of the case against former U.S. Vice President Joe Biden’s son Hunter. The U.S. House of Representatives has launched an impeachment inquiry into Trump to determine whether he pressured Zelenskyy to investigate Biden, one of his main rivals in the upcoming presidential elections in the United States, during the telephone conversation. Trump has denied pressuring Ukraine to investigate Biden during this telephone conversation and demanded an apology from his political opponents.