On Thursday, U.S. President Donald Trump and the top U.S. diplomat once again raised the possibility of U.S. military intervention in Cuba.

Secretary of State Marco Rubio, the son of Cuban immigrants, has long taken a hard line against Cuba’s socialist leadership. He said the Trump administration hopes to resolve its differences with Cuba peacefully, but he doubts the U.S. can reach a diplomatic solution with Cuba’s current government.

Trump’s “preference is always a negotiated agreement that’s peaceful. That’s always our preference. That remains our preference with Cuba,” Rubia said before boarding a flight in Miami to attend a NATO meeting in Sweden and visit India.

In recent months, senior Trump aides—including Rubio, CIA chief Ratcliffe, and other high-ranking national security officials—have met with Cuban officials to explore the possibility of improving relations between the two countries. However, the U.S. side has shown no interest in these talks, leading to the imposition of additional sanctions against the Cuban government over the past week.