Russian officials say Moscow will continue to support a Russian woman in custody in the United States who has pleaded guilty to acting as a covert agent of the Russian government, even though it rejects that claim.

Maria Butina on Thursday pleaded guilty to a conspiracy charge for trying to infiltrate conservative political groups in the U.S., as part of a deal with federal prosecutors.

Russian Foreign Minister Sergey Lavrov told Russian news agencies on Friday that he "understands" why Butina pleaded guilty, quoting what he described as "torturous" prison conditions.

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Lavrov reiterated Moscow's commitment to support Butina, who has been in jail since July, and said Russia would do it best to help her come home.

Russian President Vladimir Putin's spokesman Dmitry Peskov reiterated on Friday that the Kremlin considers all U.S. allegations against Butina "absolutely groundless."

Butina pleaded guilty Thursday to one count of conspiracy at the U.S. District Court in Washington, D.C., telling Judge Tanya Chutkan that she did commit the crime she was accused of and that she understood the plea agreement.

Her attorney, Robert Driscoll, and attorneys for the government acknowledged that Butina was in the process of cooperating with the government as part of her plea agreement.

Butina, 30, was indicted in July on charges of conspiracy and acting as a foreign agent. On Thursday, she admitted to infiltrating influential political groups in the U.S. on behalf of high-ranking Russian officials with ties to Russian President Vladimir Putin. Specifically, CBS News' Robert Legare reported that Butina pleaded guilty to working with a deputy governor of the Russian Central Bank, believed to be Alexander Torshin.

In the original indictment, the government alleged that Butina and the Russian official, who were not registered as foreign agents or diplomats, met "for the purpose of developing and executing a plan to identify and exploit personal connections with U.S. persons having influence in American politics" to advance Russian interests.

Butina pleaded guilty to the statement of offense, which said that early as March 2015 and until 2018, Butina worked with Russian officials to infiltrate and influence U.S. political groups, most notably the National Riffle Association.

The government alleged that Butina had told Russian officials that a candidate in "Party 1" was poised to win the 2016 presidential election and that she had come into contact with a U.S. official who later became a declared presidential candidate. No further details were given in court, however.