U.S. intelligence services believe Cuba is preparing for a "probable presidential transition in 2018," Director of National Intelligence James Clapper said Tuesday.

"Cuban leaders will remain focused on preserving political control as they prepare for a probable presidential transition in 2018," said the annual report to the U.S. intelligence community presented Tuesday by Clapper before the Senate Armed Services Committee.

The report also foresees that "economic reforms to reduce the state role in the economy and promote private economic activity will continue at a slow pace."

U.S. intelligence services attribute the latter in part to the "probable resistance from senior leaders and government officials concerned that rapid changes might provoke popular unrest."

The report predicts that living conditions in Cuba will remain "poor," which, together with fears that the United States will one day revoke the Cuban Adjustment Act, which allows migrants to become legal permanent residents, will "sustain the increasing migration of undocumented Cubans."

The report recalls that this Cuban migration has been particularly numerous on the southwestern U.S. border with Mexico, where in fiscal year 2015, which ended last Sept. 30, some 31,000 Cubans entered the country requesting political refugee status under the "wet foot, dry foot" statute, and obtained residency.

That number was 76 percent higher than the amount of Cubans who crossed the same border in the previous fiscal year, the report says.

Cuban President Raul Castro inaugurated in February 2013 his second 5-year term in office, which should end in 2018 and will probably be his last, according to his stated intention to limit political terms to a maximum of 10 years.