Russia on Saturday condemned the US attack on Venezuela urged it to release its leader Nicolas Maduro, who was grabbed during a military operation in and around Caracas.

"We strongly urge the American leadership to reconsider its position and release the legally elected president of the sovereign country and his wife," the Russian foreign ministry said.

In a series of statements, the ministry called for dialogue between Washington and Venezuela's leftist government and expressed "solidarity" with Venezuela's people. It stopped short, however, of offering immediate military or financial assistance to its ally.

"This morning, the United States committed an act of armed aggression against Venezuela. This is deeply concerning and condemnable," the ministry said in a statement.

"The pretexts used to justify such actions are untenable. Ideological hostility has triumphed over businesslike pragmatism," it added.

Moscow, one of only a handful of countries to congratulate Maduro on his disputed re-election in 2024, described reports of the embattled Venezuelan leader's capture by US forces as "deeply alarming".

Venezuela is Russia's closest partner in South America and a major buyer of Russian military hardware.

Moscow on Saturday rejected as "fake" reports that Venezuelan Vice President Delcy Rodriguez was in Russia.