WASHINGTON, D.C. — Former Defense Secretary Robert Gates warned that a collapse of Cuba's economy could prompt a mass migration of tens of thousands of Cubans to the United States. "The biggest risk is that we end up with another Mariel evacuation from Cuba that has tens of thousands of Cubans heading to the United States out of desperation," Gates said.

Gates described the prospect of state failure on the island as the central concern for U.S. policymakers. "Other than in these, if you will, peripheral ways, I think the main threat is, frankly, is collapse," he said.

The Mariel Boatlift saw about 125,000 Cubans seek refuge in the U.S. in 1980, as Cuba's failing economy that year led to dissent on the island. The mass exodus strained social services in Florida and led the state and federal governments to declare a state of emergency.

Gates said Cuba's involvement in providing security for ousted Venezuelan President Nicolás Maduro has impacted U.S. national security. President Trump has threatened the possibility of military action against Cuba for months, and the Trump administration has imposed an oil blockade on the country.

Cuba has run out of fuel largely as a result of the blockade, the country's energy minister said in a recent statement. Before the collapse of the Soviet Union, which had heavily subsidized Cuba's economy, the island relied on Moscow for financial support.

Secretary of State Marco Rubio has called for economic and political reforms in Cuba. The Trump administration's pressure on Havana has included the oil blockade as well as the threat of military action, measures that Gates addressed in his remarks on the risk of state collapse.