US President Donald Trump has never been to Ukraine and has shown little interest in the country. In the past, he has accused the former Soviet Republic of attempting to sabotage his 2016 election campaign. At the time, information from Kyiv led to the resignation of his campaign chairman Paul Manafort, who earlier had advised a pro-Russian party in Ukraine and was later sentenced to prison for charges relating to his foreign lobbying work. 

Against that backdrop, Trump's relationship with former Ukrainian President Petro Poroshenko was reserved when he entered the White House in 2017. But in a telephone conversation with Poroshenko's successor, Volodymyr Zelenskiy, in July, Trump didn't hold back his praise for Ukraine: "It's a great country. I have many Ukrainian friends, they're incredible people." The call in question has since sparked an impeachment investigation in the US Congress.

Viktor Pinchuk 

Billionaire Viktor Pinchuk is perhaps Trump's most prominent Ukrainian friend. His name is linked with one of Trump's first public appearances on the subject of Ukraine. In September 2015 Trump, then a Republican primary candidate for the presidency, participated in via video-transmission in the YES summit, a private event where Western politicians and experts discussed Ukraine's relations with the West.

Read more: Ukraine's Zelenskiy is a servant of Donald Trump

Pinchuk is one of the wealthiest people in Ukraine. The 58-year-old son-in-law of former Ukrainian President Leonid Kuchma comes from Dnipro (formerly Dnipropetrovsk). He owns a pipe manufacturing firm and a media conglomerate.

Trump's performance at the YES summit lasted around 20 minutes and cost Pinchuk $150,000 (€137,000), according to media reports. Whether the two men have joint business interests in not known. The forum was moderated by Douglas Schoen, a US publicist, political scientist and commentator at Trump's favorite TV channel Fox News. Schoen has worked for Pinchuk for some time and is registered as his official lobbyist with the US Justice Department. Trump said back then that he knew "many people who live in the Ukraine," called them "fantastic," and praised Pinchuk. "Viktor I've known for a long time and he is a tremendous guy," Trump said. "When he was up seeing me I said I think I can learn more from you than you can learn from me." Trump also said what he repeated four years later in the telephone conversation with Zelenskiy, namely that European states, including Germany, were not doing enough for Ukraine.

Read more: What does Germany do for Ukraine?

Pavel Fuks 

Pavel Fuks is a 47-year-old entrepreneur and millionaire from the eastern Ukrainian city of Kharkiv. He worked for a long time in Russia and founded a large real estate company there. In an interview with Bloomberg, Fuks said he got to know Trump in 2005 and met many times with him and his children, Ivanka and Donald Jr. They discussed the idea of building a Trump Tower in Moscow, Fuks said. The deal was called off apparently because Trump, according to Fuks, wanted a higher price.

Read more: How Ukrainians are reacting to the Zelenskiy-Trump affair

Fuks currently lives in Ukraine and is on a sanctions list in Russia. Fuks was one of the Ukrainians who traveled to Washington for Trump's inauguration in January 2017, but did not get to attend the swearing-in ceremony itself.

Later that same year Fuks organized a visit to Kharkiv for former New York City Mayor Rudy Giuliani. Giuliani now serves as Trump's personal lawyer and is a central figure in the scandal surrounding the Zelenskiy call. According to official sources, Giuliani traveled to Kharkiv in order to share his experience as mayor of New York City in the aftermath of the 9/11 terrorist attacks. During Ukraine's presidential election in the spring of 2019, Ukrainian media reported that Fuks had helped finance Zelenskiy's campaign, which Fuks denied.

Vitali Klitschko 

Kyiv Mayor Vitali Klitschko has close ties to Giuliani and also knows Trump personally. When tension arose this summer between Klitschko and the head of Zelenskiy's presidential office, the former boxing world champion visited Giuliani in New York and published a photo of the two of them on social media. The move was an apparent attempt by Klitschko to show he had powerful friends in his corner.

The trip took place a few days after Trump's call with Zelenskiy, during which the US President said that Giuliani was the contact person for a possible investigation into the activities of former Vice President Joe Biden and his son Hunter. Klitschko recently said that he had not talked about Biden with Giuliani.

Read more: Vitali Klitschko fights to keep power in Kyiv

He and his brother Wladimir, also a former professional boxer, first got to know Trump during their sporting careers. Klitschko has said the two boxed at Trump's former Taj Mahal casino and had been Trump's guests there.

Igor Fruman and Lev Parnas 

Fruman and Parnas are businessmen from Florida, with roots and connections in Odessa. The two are also major Republican Party donors and have reportedly met Trump and Donald Jr. More importantly, they both are clients of Giuliani, and according to US media reports introduced him to top officials in Ukraine, including the former chief public prosecutor.