Fidel Castro said Thursday he doubts he'll make it to the end of Barack Obama's four-year term and instructed Cuban officials to start making their decisions without taking him into account.

In an online column titled "Reflections of Comrade Fidel," the 82-year-old Cuban leader suggested his days are numbered, saying Cuban officials "shouldn't feel bound by my occasional Reflections, my state of health or my death."

"I have had the rare privilege of observing events over such a long time. I receive information and meditate calmly on those events," he wrote. "I expect I won't enjoy that privilege in four years, when Obama's first presidential term has ended."

He didn't elaborate, but the lines had the ring of a farewell, and Castro suggested he was on his way out.

"I have reduced the Reflections as I had planned this year, so I won't interfere or get in the way of the (Communist) Party or government comrades in the constant decisions they must make," he wrote.

Castro stepped down in July 2006 to undergo emergency surgery and hasn't been seen in public since. He turned over the presidency to his younger brother Raul in February after nearly a half-century as Cuba's supreme leader, but his periodic essays have continued to carry weight.

They are diligently read in full at the top of midday and nightly radio and television newscasts before any other national or international story. At times, they have even appeared to contradict the words of his brother, the president, prompting speculation over who is really in charge.

Thursday's essay came out on a government Web site shortly before the nightly news. Newscasters did not mention it, instead reading a column Castro had released on Wednesday.

The bulk of Thursday's column was devoted to praising Obama, the 11th U.S. president since the Cuban revolution, in part for his decision to close the U.S. prison at Guantanamo Bay. Castro recalled his thoughts Tuesday as he watched Obama assume the "leadership of the empire."

"The intelligent and noble face of the first black president of the United States ... had transformed itself under the inspiration of Abraham Lincoln and Martin Luther King into a living symbol of the American dream," he wrote.

Castro praised Obama as honest, writing: "No one could doubt the sincerity of his words when he affirms that he will convert his country into a model of freedom, respect for human rights in the world and the independence of other nations."

However, Castro suggested Obama would succumb to threats greater than his own qualities: "What will he do soon, when the immense power that he has taken in his hands is absolutely useless to overcome the unsolvable, antagonistic contradictions of the (American) system?"

Obama has said he will not end the U.S. embargo on Cuba without democratic reforms on the island, but will ease limits on Cuban-Americans' visits there and on the money they send home to relatives. He has also offered to negotiate personally with Raul Castro.

The column was Castro's second in as many days. Before that, Castro hadn't been heard from in more than a month, fueling rumors that he had suffered a stroke or lapsed into a coma. Those rumors were dispelled on Wednesday when Argentine President Cristina Fernandez met with him, the first foreign leader known to have done so since Nov. 28.

Fernandez said Castro wore the track suit that has become his trademark since he fell ill.

Raul Castro, 77, said Wednesday that his older brother spends his days "thinking a lot, reading a lot, advising me, helping me."

In an interview published Thursday by the Russian news agency Itar-Tass, Raul Castro said Cuba will insist that the Obama administration close the entire U.S. naval base at Guantanamo Bay — not just the prison camp for suspected terrorists.

"We demand that not only this prison but also this base should be closed and the territory it occupies should be returned to its legal owner — the Cuban people," Castro was quoted as saying, repeating a long-standing demand.