"Trump spent the most time [at the 2007 Moscow Millionaire Fair], Millian said, with the Russian real estate tycoon Aras Agalarov, who heads the firm Crocus International. 'He met primarily with businesspeople, with several billionaires.'"
"The Committee found no evidence to support the reported claim by Sergei Millian, that Trump traveled to Russia in 2007 to attend the Millionaire's Fair."
"President of the Russian-American Chamber of Commerce, Sergei Millian, Evgeny Buryakov's business contact on the social network LinkedIn, told Kommersant that he did not see a political component in this matter."
Around the time the DOJ annouced Buryakov's guilty plea (3/11/2016), Millian appears to have become a naturalized U.S. citizen, had his name cleared by the FBI, and made his first donation to the campign.
During and after the 2016 election, three members of Glenn Simpson's goon squad (Ross, Corn, and Maremont) had asked Millian if, how, and when he became a U.S. citizen.