On Saturday, Castro called for the U.S. to lift its embargo against Cuba during his speech at the U.N. Sustainable Development Summit, his first time speaking at the United Nations.

While Castro applauded the re-establishment of diplomatic relations between Cuba and the United States, he also called the embargo an "economic, commercial and financial blockade" that brought hardship to the Cuban people and stood as the main obstacle to the country's economic development.

Castro will also deliver remarks at the U.N. General Assembly on Monday.

Earlier this month the U.S. Departments of Treasury and Commerce announced revisions to existing Cuban sanctions, the third set of regulatory changes since the President's December announcement that the United States would re-establish diplomatic relations with Cuba.

U.S. and Cuban officials have said Obama could visit the communist-run island next year, if the two countries progress sufficiently in normalization talks.

Castro last visited the United States more than a half century ago.

This summer both U.S. and Cuban embassies re-opened in Havana and Washington. In August, Secretary of State John Kerry attended the re-opening ceremony of the U.S. embassy in Cuba. It was the highest-level trip by a U.S. official to Cuba since the 1959 revolution.