(Bloomberg) — Russian Foreign Minister Sergey Lavrov said that the U.S. arrest of Russian Maria Butina on suspicion of trying to infiltrate Republican circles and acting as an unregistered foreign agent was unacceptable.

In a telephone conversation with U.S. Secretary of State Michael Pompeo, the top Russian diplomat said the charges against Butina were fabricated and called for her prompt release, according to a Foreign Ministry statement.

Butina was ordered jailed in the U.S. on July 19 until her trial on charges she conspired to establish a back channel between Russians and American politicians. She faces an additional charge of operating in the U.S. as an unregistered agent of Russia. Prosecutors said she had ties to Russia’s intelligence services and oligarchs who could offer her safe harbor. She pled not guilty.

Among other issues, Lavrov and Pompeo also discussed possible cooperation between Russia, the U.S. and other countries in solving Syria’s humanitarian crisis. They also talked about efforts to denuclearize the Korean peninsula.

The case is U.S. v. Butina, 18-cr-00218, U.S. District Court, District of Columbia (Washington).

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