Kilimnik is, according to CNN, "a close business colleague of Manafort's who prosecutors have said has close ties to Russian intelligence". He is now on house arrest at his condo in Alexandria, Virginia, and has a $10 million unsecured bail.
He remains charged with money laundering, illegal foreign lobbying and lying to federal officials.
Mueller has suggested in previous filings that Kilimnik had ties to Russia's spy agencies.
New charges have been filed against President Trump's former adviser Paul Manafort as part of the United States probe into Russian meddling.
Legal experts say Manafort's alleged efforts to convince witnesses to assert that the Hapsburg Group had only been active in Europe would have allowed Manafort to argue he had not violated FARA.
He added: "That evidence would likely be extremely damaging to Manafort at trial-if he was innocent, why would he try to engage in witness tampering?"
The witnesses that Kilimnik and Manafort approached were involved in Manafort's alleged lobbying campaign on behalf of Ukrainian's government. Four people, including Trump's former national security adviser Michael Flynn and former campaign adviser George Papadopoulos, have pleaded guilty.
Further, the new criminal charge for obstruction is significant for three reasons.
"They haven't been convicted of anything". The longtime Manafort associate once worked for the American's consulting firm in Kiev and has been described as "Manafort's Manafort".
Earlier on Friday, Mr Trump denied that he was considering pardoning Mr Manafort.
G7 Summit set for 8-9 June in Quebec, Canada
A source within the French presidency said Trump's proposal did not seem "coherent", and that it would be discussed in Quebec. That has financial markets anxious about tit-for-tit escalation that could tarnish an overall rosy global economic outlook.
Celebrities Who Suffer With Chronic Diseases
Now if that isn’t the epitome of what a BFF is, I don’t know what is! Selena continues to be on chronic medication. There is also a huge list of celebrities past like famous painter vincent Van Gogh who suffered with this disease.