At the Grand Havana Room, one of New York City's most exclusive cigar bars, the longtime acquaintances "talked about bills unpaid by our clients, about [the] overall situation in Ukraine . . . and about the current news," including the presidential campaign, according to a statement provided by Kilimnik, offering his most detailed account of his interactions with the former Trump adviser.
Kilimnik, who provided a written statement to The Washington Post through Manafort's attorney, said the previously unreported dinner was one of two meetings he had with Manafort on visits to the United States during Manafort's five months working for Trump. The first encounter was in early May 2016, about two weeks before the Trump adviser was elevated to campaign chairman.
The August dinner came about two weeks before Manafort resigned under pressure amid reports that he had received improper payments for his political work in Ukraine, allegations that he has denied.
Kilimnik is of interest to investigators on the Senate Intelligence Committee, which is examining possible links between the Trump campaign and Russia, said a person familiar with the inquiry.
Kilimnik's name also appeared this spring in a previously undisclosed subpoena sought by federal prosecutors looking for information "concerning contracts for work . . . communication or other records of correspondence" related to about two dozen people and businesses that appeared to be connected to Manafort or his wife, including some who worked with Manafort in Kiev.
The subpoena was issued by a federal grand jury in the Eastern District of Virginia, where, until recently, Manafort's business was headquartered. The subpoena did not specify whether it was related to the FBI's investigation of Russian interference in the U.S. election or a separate inquiry into Manafort's business activities. Investigators in the Eastern District of Virginia have been assisting with the Russia investigation.
In Ukraine, Kilimnik's political adversaries have said he may be working with Russian intelligence. U.S. officials have not made that charge.
Kilimnik rejected the allegation, telling The Post in his written statement that he has "no relation to the Russian or any other intelligence service."
His dinner with Manafort came as Trump's campaign chairman was facing mounting questions about his work in Ukraine and his business ties to allies of Russian President Vladimir Putin.
Kilimnik said his meetings with Manafort were "private visits" that were "in no way related to politics or the presidential campaign in the U.S." He said he did not meet with Trump or other campaign staff members, nor did he attend the Republican National Convention, which took place shortly before the Grand Havana Room session. However, he said the meetings with Manafort included discussions "related to the perception of the U.S. presidential campaign in Ukraine."
Manafort spokesman Jason Maloni said that Kilimnik was a "longtime business associate" who would have naturally been in touch with Manafort. Manafort told Politico, which first reported his relationship with Kilimnik, that his conversations included discussions about the cyberattack on the Democratic National Committee and the release of its emails.
"It would be neither surprising nor suspicious that two political consultants would chat about the political news of the day, including the DNC hack, which was in the news," Maloni said.
He added, "We're confident that serious officials will come to the conclusion that Paul's campaign conduct and interaction with Konstantin during that time was perfectly permissible and not in furtherance of some conspiracy."
Before joining Trump's campaign, Manafort had built a practice in Ukraine as an adviser to the Russia-friendly Party of Regions and helped elect former president Viktor Yanukovych, who was ousted in 2014 and fled to Russia. Manafort kept his Kiev office open until mid-2015.
Federal investigators have shown an interest in Manafort on several fronts beyond his work on behalf of Trump.
Subpoenas in New York have sought information about Manafort's real estate loans, according to NBC News. Justice Department officials also are exploring whether Manafort should have more fully disclosed his work for foreign political parties, as required by federal law.
Former FBI director Robert S. Mueller III has been appointed special counsel to oversee the Russia inquiry, and people familiar with his work said his office has now taken over investigations of Manafort's conduct unrelated directly to the Russia probe.
A spokesman for the Eastern District of Virginia declined to discuss the subpoena there. A spokesman for Mueller also declined to comment.
Manafort's relationship with Kilimnik shows the challenge facing investigators as they seek to determine whether contacts between Russian allies and Trump associates during the height of Russian interference in the campaign amounted to collusion or reflected routine interactions between people with relationships unrelated to the campaign.
Kilimnik said he grew up in southeastern Ukraine, which was then part of the Soviet Union. He said he moved to Moscow in 1987, when he was 17, and enrolled in the Military Institute of the Ministry for Defense, an elite academy for training military translators.
Kilimnik said he was trained in English and Swedish and spent the early 1990s serving as a military translator, including in 1993 on a trade mission of a Russian arms company.
He said the GRU, the military intelligence service that U.S. officials have linked to the 2016 cyberattacks, did not recruit from his language academy.
"No one ever spoke to me ever about doing any intelligence work — neither Russians or Ukrainians or any other foreign country," he said.
Some experts disputed Kilimnik's description of the Moscow academy.
Stephen Blank, a Russia expert at the American Foreign Policy Council, a Washington think tank, and a longtime former instructor at the U.S. Army War College, called the institute a "breeding ground" for intelligence officers.
Mark Galeotti, a Russia security specialist at the Institute of International Relations, a Prague-based foreign policy think tank, said the school is one of the "favored recruiting grounds" of the GRU.
In 1995, amid uncertainty in the post-Soviet economy, Kilimnik said he needed money and took a job as a translator for the International Republican Institute, a pro-democracy group affiliated with the U.S. Republican Party.
People who worked with Kilimnik said he was proficient in several languages and a savvy reader of people.
"I relied on him," said Sam Patten, who was Kilimnik's boss at the Moscow office of IRI from 2001 to 2004.
At the time, Kilimnik openly discussed his work in the Russian army, said Phil Griffin, a political consultant who hired him at the IRI. "He was completely upfront about his past work with Russian military intelligence," Griffin said. "It was no big deal."
Julia Sibley, a spokeswoman for the IRI, confirmed that Kilimnik worked for the organization a decade ago but declined to provide additional information.
In 2005, Griffin, who had left Moscow to work for Manafort in Ukraine, invited Kilimnik to join him there, according to both men.
Kilimnik said he has worked largely in Ukraine ever since, although he declined to say whether he has become a Ukrainian citizen.
Kilimnik's role for Manafort grew over time. Beyond his work as a translator, Kilimnik would "help Manafort understand the political context and why people were doing what they were doing," Patten said.
People familiar with Kilimnik's work in Ukraine for Manafort say his assignments included meeting with powerful Ukrainian politicians and serving as a liaison to Russian aluminum magnate Oleg Deripaska, who is close to Putin and did business with Manafort.
A spokeswoman for Deripaska did not respond to a request for comment.
In August, Volodymyr Ariev, a member of the Ukrainian parliament who represents a party that opposed Manafort's clients, requested that Ukraine's top prosecutor investigate whether Kilimnik had worked with Russian intelligence services.
A spokeswoman for the prosecutor did not respond to questions from The Post. The prosecutor's office told Politico in March that Kilimnik was "not being processed now as a witness, suspect or accused."
Others viewed Kilimnik as more aligned with Washington than Moscow.
Oleg Voloshin, who served as a spokesman for the foreign minister of Ukraine under Yanukovych, said Manafort and Kilimnik were pushing Yanukovych to ally with Europe rather than Russia, which angered some in Yanukovych's party.
"Kilimnik was always trying to promote this message — if you want to be successful here, you want to look westward," Voloshin said.
Kilimnik was also well known at the U.S. Embassy, and officials there and at other western embassies appeared to trust him, meeting with him frequently to discuss Ukrainian politics, said people familiar with his work.
"He's not working for the Russians," said a foreign policy expert close to Republicans who was working in Ukraine at the time. "If anything, he's working for us."
Alice Crites, Devlin Barrett and Matt Zapotosky in Washington and Andrew Roth in Moscow contributed to this report.