UN Secretary-General Ban Ki-moon said on Saturday that Fidel Castro's Cuba made strides in areas such as education and health and urged the Caribbean island to continue along its current reform path in pursuit of greater prosperity.
"At this time of national mourning, I offer the support of the United Nations to work alongside the people of the island," Efe news agency quoted Ban as saying.
The UN chief, who is attending the Global Sustainable Transport Conference in Ashgabat, Turkmenistan, extended condolences to the Cuban people and Fidel Castro's family, particularly the late revolutionary leader's brother, Cuban President Raul Castro.
"I hope that Cuba will continue to advance on a path of reform and greater prosperity," he added, referring to Raul Castro's project of "updating" Cuba's socialist economic model by allowing more scope for private enterprise and foreign investment.
Ban said he met with Fidel Castro in January 2014, adding that they had discussed topics including sustainable development and climate change.
Under the leadership of Fidel Castro, who passed away Friday night at the age of 90, Ban said that Cuba had "made advances in the fields of education, literacy and health".
Castro formally resigned as Cuba's president in 2008, two years after falling ill with diverticulitis and ceding power to his younger brother.