Prosecutors from special counsel Robert Mueller's office said Monday that former Trump campaign chairman Paul Manafort violated his plea agreement with the government by lying to federal investigators "on a variety of subject matters." Manafort was convicted of various financial crimes in August before reaching an agreement in September to cooperate with Mueller's Russia investigation.

"After signing the plea agreement, Manafort committed federal crimes by lying to the Federal Bureau of Investigation and the Special Counsel's Office on a variety of subject matters, which constitute breaches of the agreement," prosecutors said in a joint status report filed in U.S. District Court in Washington.

Attorneys for Manafort wrote in the filing that Manafort "has provided information to the government in an effort to live up to his cooperation obligations."

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"He believes he has provided truthful information and does not agree with the government's characterization or that he has breached the agreement," Manafort's lawyers wrote, asking the court to set a date for sentencing.

Manafort was convicted on eight out of 18 counts of financial crimes including bank fraud and tax fraud in federal court in Virginia in August. Prosecutors alleged Manafort hid tens of millions of dollars in overseas income over several decades, including his time as chairman of the Trump campaign in 2016. President Trump has consistently and repeatedly denied any wrongdoing.

Manafort reached a plea agreement with Mueller's office on Sept. 14 to avoid a second trial on additional charges in D.C. District Court. Under the deal, Manafort pledged "to cooperate fully, truthfully, completely, and forthrightly" with Mueller's probe and any other investigation.

Prosecutors said Monday the government will provide more details about the falsehoods in a future filing.