Russian warships armed with hypersonic missiles conducted military drills near the United States while on their way to Cuba, the Russian Defense Ministry said Tuesday.

The Admiral Gorshkov frigate and the Kazan nuclear-powered submarine participated in a missile simulation drill while in the Atlantic, according to The Associated Press. 

The Admiral Gorshkov has new Zircon hypersonic missiles, which Russian President Vladimir Putin has touted as weapons that can travel nine times faster than the speed of sound, allowing them to penetrate existing anti-missile defenses.

The Cuban Foreign Ministry said that the Russian ships will be in Havana over the next week.