Fidel Castro had not been seen or heard of for five weeks
Former Cuban leader Fidel Castro has praised US President Barack Obama for his "honesty" but says he has many questions to answer.
Mr Castro broke a five-week silence, writing an opinion column on a state-run internet site.
The 82-year-old's silence, after months of column writing, had contributed to speculation about his health.
His brother, President Raul Castro, said earlier that Mr Obama "seemed like a good man" and wished him luck.
But he cautioned that the new US president might be raising "hopes too high".
Fidel Castro's essay on the www.cubadebate.cu site came hours after the president denied rumours that his health was worsening.
He did not give any reason for not writing columns, or "reflections" as he calls them, since 15 December, after averaging nine a month in 2008.
Mr Castro, whose Cuban revolution has survived 10 US presidents, had warm words for Mr Obama.
"I expressed that personally I had not the least doubt of the honesty with which Obama, the 11th president since 1 January, 1959, expressed his ideas, but in spite of his noble intentions there remained many questions to answer," he wrote.
Mr Obama has said he wants to meet Cuban leaders and improve US-Cuba relations. He has indicated he will ease restrictions on travel and remittances to Cuba but maintain the 46-year US trade embargo on the island.
The Cuban president has also said he is willing to talk with Mr Obama, as long as there are no intermediaries and as equal parties to the dialogue.
If they met, it would be the first between leaders from the neighbouring nations in five decades.
Fidel Castro also confirmed that he had met Argentine President Cristina Fernandez de Kirchner on Wednesday, near the end of her three-day visit to Havana.
President Fernandez said earlier that Mr Castro seemed healthy after she spent an hour of talks with him in Havana.
No pictures of the talks have yet been released.