Russian Foreign Minister Sergei Lavrov stated on Monday that economic and military “pressure” exerted on its ally Cuba is “unacceptable.” His comments followed heightened threats from the Trump administration against the communist nation.

Recently, U.S. President Donald Trump issued an executive order imposing the potential for increased tariffs on nations supplying oil to Cuba, which is currently enduring its worst economic crisis in decades.

Cuban President Miguel Díaz-Canel condemned this action, labeling it an effort to “suffocate” the Cuban economy.

Lavrov emphasized the “unacceptability of any economic or military pressure on Cuba, including interruptions to the island’s energy supply,” as noted in a readout of his conversation with Cuban Foreign Minister Bruno Rodriguez.

He remarked that any disruption in energy supplies could “seriously aggravate the economic and humanitarian circumstances in the country” and reiterated Russia’s “strong commitment to continue offering Cuba vital political and material support.”

Reporters from AFP have observed long lines of Cubans at gas stations in Havana following the U.S. tariff announcement.

Tensions between the United States and Cuba have intensified in light of the Trump administration’s unexpected actions regarding Venezuelan President Nicolás Maduro, whose country has been a significant source of oil for Cuba.

Moreover, prior to this, the Caribbean island had been grappling with frequent blackouts amid its most severe economic crisis since the Soviet Union’s collapse in 1991, which had been its main supporter.