MEXICO CITY, Mexico - Cuba says it has disrupted a Russian scheme to recruit its citizens to fight in Ukraine.

In a statement, Cuba's foreign ministry called the scheme a human trafficking ring. It said Cubans, both in Russia and on the island, had been recruited to fight in Russia's war against Ukraine.

Cuba is facing the worst economic crisis in decades. The government is struggling to keep the lights on and Cubans are struggling to keep food on their tables. If already bad relations with the U.S. deteriorate, things could get worse.

Over the past few months, Cuba has been diligent in batting back any suggestion that it is helping Russia in this conflict.

"Cuba plays no role in the war in Ukraine," the statement read. "It is acting and will act vigorously against whoever, from the national territory, participates in any form of human trafficking for the purposes of recruitment of mercenaries so that Cuban citizens use weapons against any country." Without giving details, Cuba says it has begun prosecuting those involved in the recruitment.

The statement strikes a rare note of discord between the two allies. Historically the Cuban government has had close relations Russian government since the revolution in 1959 and sided with them during the Cold War.

The Russian foreign minister travelled to Cuba in April as part of a tour of Russia's Latin American allies and most recently the Cuban defense minister held talks with his counterpart in Moscow. At the end of last year, Cuban President Miguel Díaz-Canel met his Russian counterpart Vladimir Putin in Moscow, in a bid to renew ties.

In late May, a Russia newspaper in Ryazan city reported over a dozen Cuban citizens had joined Russia's armed forces to fight in Ukraine, in return for Russian citizenship. The reports have not been independently verified. The statement comes at a time Russia is actively recruiting to boost the size of its armed forces fighting in Ukraine.

Moscow has yet to comment on the allegations.