Former Cuban leader Fidel Castro has broken his silence on the recent shift in US-Cuba relations with a cautiously-worded message on the recent detente.

The retired leader said though he does not "trust the United States" in their policies he supports any initiative in resolving the conflict between the countries.

In a televised statement attributed to the Cuban revolutionary leader, he said: "I don't trust the policy of the United States, nor have I exchanged a word with them, but this does not mean I reject a pacific solution to the conflicts.

"We will always defend cooperation and friendship with all the people of the world, including with our political adversaries."

The letter, sent to the University Students Federation in Havana and also published in a Communist Party daily, has come a week after American and Cuban delegates held landmark talks in the Cuban capital to work towards 'normalisation' of relations between the two countries.

The statement from Castro read: "Any peaceful or negotiated solution to the problems between the United States and the peoples or any people of Latin America that doesn't imply force or the use of force should be treated in accordance with international norms and principles."

Earlier in December 2014, Obama announced that a "new chapter" was set to begin between Havana and Washington after several decades of standoff. The two countries embarked on a historic prisoner exchange deal following 18-month-long secret talks.

The Obama administration has been facing severe criticism domestically over the new, more open relationship, which critics claim ignores Cuba's purported human rights violations.

The elder Castro's silence over the latest development, which was announced on 17 December, led to frenzied speculation over his health, with some even claiming he had died.