Updated

Fidel Castro on Thursday threw his first punch at President Obama after several weeks of praise for the new leader, demanding the U.S. return Guantanamo Bay military base to Cuba and criticizing the U.S. defense of Israel.

Castro's latest essay, published on an official Web site, came one week after he called Obama "intelligent and noble" and said he would cut back on his writings to prevent interfering with Cuban government decisions.

The missive Thursday raised new questions about what role he maintains in policy-making, especially coming while his brother, President Raul Castro, was in Moscow on an official visit.

The ailing 82-year-old former president wrote that if the U.S. doesn't give the U.S. base at Guantanamo back to Cuba, it will be a violation of international law and an abuse of American power against a small country.

The U.S. president must "respect this norm without any condition," Castro wrote.

Obama has ordered the prison for terror suspects on the U.S. base to be closed within a year, but Cuba also demands the return of the 45-square-mile territory the base occupies in the island's east. Raul Castro and other government officials have called for the return of the base, but with less critical words and tone.

The U.S., which acquired Guantanamo more than 100 years ago, considers it strategically important to maintain. The treaty granting its use remains in effect unless both Cuba and the U.S. abrogate it or the U.S. abandons the base.

The mission for Guantanamo "remains constant," spokesman Navy Chief Petty Officer Lewis Mesta told The Associated Press on Wednesday. "We will continue to provide logistical support for all U.S. Naval vessels who operate in the Caribbean theater."

In his Thursday essay, Castro also criticized Obama for backing Israel's defense against attacks by Palestinian militants. He said it demonstrated "the abusive character of the empire's power" and insisted it would contribute to "the genocide against the Palestinians."

Castro stepped aside after undergoing abdominal surgery 2 1/2 years ago and has not been seen in public since. His 77-year-old brother permanently replaced him as president nearly a year ago.

In an essay last week, Castro had praised Obama for "the sincerity of his words" and as "a living symbol of the American dream."

Castro wrote on Jan. 22 that he was cutting back on his occasional columns, known as "Reflections of Comrade Fidel," so he won't "interfere or get in the way of the (Communist) Party or government comrades in the constant decisions they must make."

He also said in that essay that he is unlikely to live through the end of Obama's four-year term, and that Cuban officials "shouldn't feel bound by my occasional Reflections, my state of health or my death."

Fidel Castro's essays have continued to carry weight and are diligently read in full at the top of midday and nightly radio and television newscasts before other national or international news. Thursday's essay arrived too late to make the evening news, which focused on Raul Castro's visit to Russia.