Secretary of State Marco Rubio announced new sanctions Thursday on Cuba's military-industrial enterprise, its leader and a state-owned natural resources company.Why it matters: The new sanctions show the Trump administration is pushing forward for regime change in Cuba, a long-held goal of Rubio and President Trump.Zoom in: Rubio imposed the sanctions under Trump's May 1 executive order targeting "Those Responsible for Repression in Cuba and for Threats to United States National Security and Foreign Policy." The sanctioned include:GRUPO DE ADMINISTRACION EMPRESARIAL S.A. Known as GAESA, it is the Cuban military-controlled umbrella enterprise, which Rubio called "the heart of Cuba's kleptocratic communist system" that controls major parts of the country's economy, including hotels.ANIA GUILLERMINA LASTRES MORERA. Lastres is, or has been, a senior leader or member of GAESA's board of directors.MOA NICKEL SA. Known as MNSA, it operates the metals and mining sector of the Cuban economy. Rubio said it "has exploited Cuba's natural resources to benefit the regime at the expense of the Cuban people. It profits from assets that were originally expropriated by the Cuban regime from U.S. persons and corporations."Zoom out: Rubio's announcement comes days after the State Department began detailing personnel to U.S. Southern Command in Miami in anticipation of further potential hostilities with Cuba, according to a source.The State Department is also beefing up its disaster-preparedness supply center in South Florida.What they are saying: "These sanctions are part of the Trump Administration's comprehensive campaign to address the pressing national security threats posed by Cuba's communist regime and hold accountable the regime and those who provide it material or financial support," Rubio's announcement stated."Just 90 miles from the American homeland, the Cuban regime has brought the island to ruin and auctioned off the island as a platform for foreign intelligence, military and terror operations."What's next: Trump and Rubio have not ruled out military action and, Rubio said, "additional designations can be expected in the following days and weeks."