In the public portion of the 10-page document, filed in Washington federal court, Manafort's lawyers wrote that their client couldn't remember or incorrectly recalled specific events from his past dealings with Kilimnik.
The former Trump campaign chairman on Tuesday denied in a filing from his defense team that he broke his plea deal by lying repeatedly to prosecutors working for special counsel Robert Mueller III about that and other issues.
In another action that may be related to the ongoing Russian Federation probe, the Supreme Court Tuesday denied an application for a stay in a case involving a bank owned by a foreign government.
According to the filing, Manafort discussed a Ukrainian peace plan with his close Russian-intelligence-linked associate, Konstantin Kilimnik.
I was focused yesterday on the indictment of Natalia Veselnitskaya and only considered briefly the apparently inadvertent disclosures by Paul Manafort's lawyers concerning their client's contacts with a business associate with ties to Russian intelligence. Kilimnik has been charged alongside Manafort with witness tampering as part of Mueller's sprawling investigation into Russian interference in the presidential election and is believed to have links to the GRU, the Russian intelligence unit blamed for hacking Democrats' emails in 2016.
Kilimnik has always been suspected to be central to Mueller's investigation into Russian influence in the 2016 presidential election.
Much of the information about Kilimnik was redacted in the filing, although Manafort admitted he conspired with Kilimnik to obstruct justice.
Manafort, after being convicted of various bank and tax fraud charges, had agreed last September to cooperate with special counsel Robert Mueller's ongoing investigation into allegations of collusion between Trump's campaign and Russian Federation.
Manafort spokesman Jason Maloni said the Madrid trip mentioned in the filing occurred in January or February 2017 - months after Manafort was ousted from the campaign and as Mr Trump was taking office.
The filing also showed that Mueller accused Manafort of discussing a "Ukraine peace plan" with Kilimnik and meeting with him in Madrid at some point during the 2016 campaign.
After leveling that accusation, prosecutors filed a heavily-redacted court document describing five areas in which Manafort is accused of lying to government investigators, including misleading statements about his contacts with Trump administration officials.
Manafort's lawyers have argued he provided truthful information to the best of his ability at the time. Prosecutors say Manafort acknowledged the meeting only after being told that they were in the same city on the same day. "This does not constitute outreach by Mr. Manafort to the President", a redacted line in the filing claims, while another redacted sentence says another identified interaction is "hearsay purportedly offered by an undisclosed third party".
"For several months Mr. Manafort has suffered from severe gout, at times confining him to a wheelchair", the lawyers wrote.
U.S. District Judge Amy Berman Jackson had given Manafort's lawyers until Monday to make a decision. Manafort was convicted by a jury in a Virginia federal court for eight tax and bank fraud charges. In return, prosecutors said they would consider asking the judge for leniency at his eventual sentencing.