Politics

Kenneth P. Vogel, Scott Shane,

Mark Mazzetti and Iuliia Mendel

        WASHINGTON — Hours after he was sworn in as America’s 45th president, Donald J. Trump and his wife, Melania, swayed together to a rendition of the Frank Sinatra classic “My Way,” as hundreds of their wealthiest and most influential supporters held aloft smartphones to capture the Trumps’ first dance following the inauguration.

        Serhiy Kivalov, a Ukrainian lawmaker known for pro-Russian initiatives, took photos of the dance, as well as of his coveted tickets and passes to the soiree where it took place, the Liberty Ball at the Walter E. Washington Convention Center, posting them on Facebook and declaring that “it was an honor” to attend.

        He was one of at least a dozen Ukrainian political and business figures who made their way to Washington for the inauguration, several of whom attended the Liberty Ball. Most had more on their dance cards than just parties.

        They attended meetings and orchestrated encounters at Trump International Hotel with influential Republican members of Congress and close allies of President Trump. Representing a range of views, including a contingent seen as sympathetic to Moscow, they positioned themselves as brokers who could help solve one of the thorniest foreign policy problems facing the new administration — the ugly military stalemate between Russia and Ukraine and the tough sanctions imposed on Moscow following its seizure of Crimea.

        The transition of power in Washington attracted officials and business executives from around the world seeking entree and influence with the new administration. While many parties and other gatherings during that period were open to anyone, packages for more exclusive events organized by Mr. Trump’s presidential inaugural committee started at $25,000 for two tickets to one of the official black tie balls and other events, according to a brochure listing inaugural committee “underwriter benefits.”

        Evidence of the Ukrainians’ presence eventually prompted interest from the special counsel, Robert S. Mueller III, as he investigated Russian interference in the 2016 election, and has spawned a number of related inquiries by federal prosecutors. The investigations are playing out against growing indications that some of the Ukrainians who came to Washington for the inaugural, or their allies, were promoting grand bargains, or “peace” plans, that aligned with Russia’s interests, including by lifting sanctions.

        Such a deal would not just have given the new administration additional flexibility to bring Moscow into American diplomatic efforts in the Middle East, but could also have eased the way for a cast of characters with ties to Mr. Trump — some of whom in turn had ties to the Ukrainians who came to Washington — to move ahead on business deals that had been complicated by the sanctions.

        Federal prosecutors have asked witnesses about how some of the Ukrainians gained access to inauguration events, whom they met with while they were in the United States, and what they discussed — including questions about various peace plan proposals — according to people with direct knowledge of the questions and others who were briefed on the interviews.

        As recently as last month, prosecutors were asking witnesses about illegal foreign lobbying related to Ukraine. Another subject of questions has been whether foreigners from Ukraine and other countries used straw donors to disguise donations to the inaugural committee. Federal law prohibits foreigners from contributing to an inaugural committee, although they can attend events if Americans buy the tickets.

        Elements of the investigations have gotten new visibility in recent weeks.

        Lawyers for Paul Manafort, the former Trump campaign chairman who was paid tens of millions of dollars over the last dozen years by Russia-aligned Ukrainian interests, inadvertently revealed on Tuesday that he had communicated about a Ukraine-Russia peace plan with a business associate believed to have ties to Russian intelligence.

        The associate, Konstantin V. Kilimnik, is a Russian citizen who has been charged by Mr. Mueller with obstruction of justice for trying to shape the testimony of witnesses to the events that led to charges of illegal foreign lobbying against Mr. Manafort.

        Mr. Kilimnik was said in the inadvertently disclosed portions of the court filing to have received political polling data from Mr. Manafort in 2016. Mr. Manafort relayed a request to have Mr. Kilimnik pass the polling data to two Ukrainian oligarchs who had arranged or provided financing for Russia-aligned Ukrainian political parties for which Mr. Manafort had worked. One of the oligarchs, Serhiy Lyovochkin, attended the Liberty Ball, according to one person familiar with the guest list and another who saw him there.

        Last month, prosecutors made a move that was seen as signaling the continuing cooperation of Sam Patten, an American consultant who had worked with Mr. Kilimnik and Russia-aligned Ukrainians looking to build ties to the Trump administration.

        Mr. Patten had pleaded guilty in late August to charges including funneling $50,000 in money from an unnamed foreigner who matched the description of Mr. Lyovochkin but was described in court papers only as “a prominent Ukraine oligarch” to buy tickets to exclusive Trump inauguration events for the oligarch, Mr. Kilimnik and someone described only as “another Ukrainian.”

        Other Ukrainians who came to Washington during the inauguration said prosecutors had been asking wide-ranging questions.

        “I have been interrogated twice by the F.B.I. and Mr. Mueller,” said Andrii V. Artemenko, who came to the inauguration as a Ukrainian member of Parliament bearing a peace proposal that was later criticized as pro-Russian.

        Mr. Artemenko said he had testified before Mr. Mueller’s grand jury last summer and had answered questions from the Mueller team “about what is my purpose of this trip, how I can get there, and what I did, how I got invitations and tickets and stuff.”

        On Capitol Hill, investigators from the House Oversight Committee, now under Democratic control, are looking into Michael T. Flynn, Mr. Trump’s first national security adviser, who was a central player in the effort to build a new relationship with President Vladimir V. Putin of Russia.

        How active a role Mr. Flynn played in the discussions about a peace plan for Ukraine is unclear, but congressional investigators have been pursuing whether he or his former business partners might have gained financially if the sanctions on Russia were ended.

        The committee, whose chairman is Representative Elijah E. Cummings of Maryland, is continuing to pursue its investigation of Mr. Flynn’s business dealings and “his potential misuse of his public position when he was national security adviser,” a committee spokeswoman said.

        In 2017, a whistle-blower told committee investigators that Mr. Flynn had mentioned to a business associate around the time of the inauguration that the Russia sanctions would be “ripped up” as one of the administration’s first acts. Mr. Flynn believed that ending the sanctions could allow a business project he had once participated in to move forward, according to the whistle-blower.

        Mr. Flynn had been part of a business venture to partner with Russia to build nuclear power plants in the Middle East until June 2016, but after his direct involvement ended, he remained close with people involved in the project.

        In a December 2017 letter to the Oversight Committee, an officer of the company that hired Mr. Flynn as an adviser on the project, ACU Strategic Partners, said that the allegations of the whistle-blower were “false and unfounded.”