Yes, Fidel Castro said this in 2014: ‘Xi Jinping is one of the strongest and most capable revolutionary leaders I have met in my life’.
This is noted in an article by Ajit Singh called ‘China: A Revolutionary Present’ (well worth a read).
A couple of decades earlier, Fidel also observed:
I think China is a socialist country, and Vietnam is a socialist nation as well. And they insist that they have introduced all the necessary reforms in order to motivate national development and to continue seeking the objectives of socialism. There are no fully pure regimes or systems. In Cuba, for instance, we have many forms of private property. We have hundreds of thousands of farm owners … Practically all Cubans own their own home and, what is more, we welcome foreign investment. But that does not mean that Cuba has stopped being socialist.