Russia sentenced an unidentified American man to a six-year prison sentence Monday for attempting to take his 4-year-old, Russian-born son out of the country illegally.

A court in Russia’s Kaliningrad region said the father tried to flee to Poland with his son after a visit with the child in Kaliningrad in July 2023.

The court said in a statement on Telegram that the man had not obtained the mother’s consent to take their child out of the country.

The statement said the father and son drove most of the way to the Polish border, before exiting their vehicle in an attempt to “cross the border through the forest and the swamp.”

Russian border guards discovered the pair and detained the father.

The American’s prison sentence comes amid frayed ties between the U.S. and Russia, which are at their lowest levels since the Cold War era due to the Russian assault on Ukraine.

Several American prisoners are in Russian prisons on various charges.

However, in a recent historic prisoner swap, the West released Russian spies who were being held and Russia freed, among others, U.S.-Russian dual national Alsu Kurmasheva, a Radio Liberty/Radio Free Europe journalist who traveled to Russia in May 2023 to visit her ailing mother in the Tatarstan city of Kazan.

Authorities blocked Kurmasheva from leaving the country and later jailed her for more than nine months for allegedly spreading "false information" about the Russian military, charges that were seen widely as retaliatory.

Some information in this report was provided by The Associated Press and Agence France-Presse.