Cuba's former president and revolutionary leader Fidel Castro expressed his cautious support for the peaceful solution to the 50-year-odd controversy with the United States.

In a message to the University Young Federation published Tuesday by Cuba's official daily "Granma", Castro, 88, wrote that he does not trust the U.S. policies, but that does not mean a rejection to a peaceful solution of conflicts and dangers of war.

"Defending peace is a duty of all," said the veteran revolutionary.

"Any peaceful and negotiated solution to the problems between the United States and the peoples or any people of Latin America, not involving force or the use of force, should be handled according to international principles and standards," he said.

"We will always defend the cooperation and friendship with all peoples of the world, including those of our political opponents," he added.

Castro stressed that the Cuban president (Raul Castro) has taken appropriate steps according to his prerogatives and powers granted by the National Assembly and the Communist Party of Cuba.

This is the first time that the former Cuban leader spoke of the resumption of diplomatic relations between Cuba and the United States, which was announced by U.S. President Barack Obama and Cuban President Raul Castro on Dec. 17.

The two sides have held talks in Havana to identify the steps for restoring the diplomatic ties, reopening the embassies in each other's capital cities, and expanding the cooperation in several fields.

However, Cuban and U.S. officials attending negotiations told reporters on Friday that the U.S. policy change towards the island country is "a tactical one."