The filing completed Manafort's registration under the Foreign Agents Registration Act, known as FARA, one of several legal issues that have been the focus of scrutiny by the FBI and Justice Department prosecutors, according to US officials briefed on the investigation.
The registration doesn't end the years-long US probe of Manafort and his firm which, because of Manafort's role as Trump campaign chairman last year, have become part of the broader investigation now led by special counsel Robert Mueller looking into Russian meddling in the 2016 election.
US investigators continue to scrutinize Manafort's tax and business records to determine whether any criminal violations occurred, according to the officials briefed on the investigation.
Jason Maloni, Manafort's spokesman, said Manafort "started this process in concert with the FARA unit in September, before the outcome of the election and well before any formal investigation of election interference began. Paul's primary focus was always directed at domestic Ukrainian political campaign work, and that is reflected in today's filing."
The documents filed Tuesday largely center on work done for Ukraine's Party of Regions by Manafort and his firm DMP International, which occurred long before Manafort joined the Trump campaign.
Richard Gates, listed as an employee of the firm, also completed his registration as a foreign agent with the documents filed Tuesday.
Gates worked as a deputy to Manafort on the Trump campaign. A June 15 memo from the Trump transition team's general counsel directed transition staffers and volunteers to preserve records related to Gates and Manafort, among other campaign associates.
An attorney for Gates did not respond to CNN's request for comment.
The filings record $3.9 million in expenses related to the firm's work for the Party of Regions, which included costs for travel, living expenses and payments to various contractors during the 2012-2014 period. This included $531,000 paid to Konstantin Kilimnik, a Ukraine-based business associate helping Manafort's work with the country's former leader Viktor Yanukovych, who fled to Russia after being ousted in a popular revolt.
The documents say that Manafort's firm focused on "electing Party of Regions' candidates" and adds that the firm "communicated with the US embassy regarding developing events in the Ukraine" and "provided strategic counsel and advice to members of the Party of Regions regarding their interactions with US government officials."
The Manafort filings disclose one meeting with a member of Congress, Republican Rep. Dana Rohrabacher of California, in March 2013, as well as a $1,000 contribution to Rohrabacher.
Rohrabacher has been a proponent of improved US ties to Russia and for the Trump administration to treat Russia as a partner and friend of the US.
Rohrabacher told CNN he remembers having dinner with Manafort in 2013 due to his position as chairman of the House subcommittee on Europe, Eurasia and emerging threats.
"I'm sure his thoughts on what was going on in Ukraine were part of the discussion," said Rohrabacher, who described Manafort as an old friend.
Anti-corruption authorities in Ukraine named Manafort in an investigation last summer after a ledger allegedly showed millions of dollars in undisclosed payments to Manafort. In a statement, Manafort said, "I have never received a single 'off-the-books cash payment.'"
A Ukrainian prosecutor involved in the probe told a Ukrainian news outlet this week that Manafort's signatures do not appear in the ledger, so he does not have enough evidence to prosecute.