Suspected Russian secret agent Maria Butina set to agree plea deal with US prosecutors

Court filings show lawyers 'remain optimistic about a pre-trial resolution'

Maria Butina speaks to a crowd during a rally in support of legalising the possession of handguns in Moscow in 2013 (AP)

A women suspected of being a Russian secret agent is set to agree a plea deal with US prosecutors ahead of her criminal case, according to court documents.

Lawyers for Maria Butina and federal prosecutors wrote in the joint court filing they "remain optimistic about a pre-trial resolution" for her case.

The filing follows similar court papers which were filed earlier this month which demonstrates negotiations between the two parties continue.

The 30-year-old is accused of gathering intelligence on American officials and political organisations by developing relationships with politicians through her contacts with the National Rifle Association (NRA).

The accusations claim her work was directed by a former Russian lawmakers with ties to Russian President Vladimir Putin.

Ms Butina is charged with conspiracy and acting as an unregistered foreign agent for Russia.

She has mounted an aggressive defence since she was jailed in July and her legal team tried to have the case thrown out earlier this month.

Ms Butina has pleaded not guilty and her lawyers have said she is a student interested in American politics and better US-Russian relations.

Her case is unrelated to special counsel Robert Mueller's investigation into Russian election interference and a hearing is scheduled for next month.

Agencies contributed to this report