(AP) -- Texas Sen. Ted Cruz says President Barack Obama should not travel to Cuba next month.

The White House is planning to make the announcement about the visit as early as Thursday.

But asked about reports of the president's plans on Wednesday night during a town hall in South Carolina broadcast on CNN, the Republican candidate for president said Obama shouldn't make the trip "as long as the Castros are in power."

Cruz's father was born in Cuba, where he was arrested and jailed before fleeing to the United States in the 1950. "My father has seen firsthand the evil and oppression in Cuba," Cruz said.

Cruz is also speaking out against any plans of closing the prison in Guantanamo Bay, Cuba, saying he fears Obama will do so before leaving office next year.