A U.S. judge on Tuesday postponed a plea agreement hearing for accused Russian agent Maria Butina by one day, until Thursday.

Butina, accused by U.S. prosecutors of acting as a Russian agent to infiltrate the powerful National Rifle Association lobby group and influence American policy toward Moscow, was expected to plea guilty. Butina initially pleaded not guilty after being charged in July with acting as an agent of Russia's government and conspiracy to take actions on behalf of Moscow.

U.S. District Court Judge Tanya Chutkan did not specify a reason for the delay.

Butina was jailed awaiting trial. Moscow has labeled the case against Butina "fabricated" and called for her release.

Prosecutors have accused Butina of working with a Russian official and two U.S. citizens to try to infiltrate the NRA, which has close ties to Republican politicians including President Donald Trump, and sway Washington's policy toward Moscow.

The federal prosecutors in the case against Butina are not from the office of Special Counsel Robert Mueller, who is investigating Russia's role in the 2016 U.S. election and whether Trump's campaign conspired with Moscow.