A 12 Feb 2009 file photo of Cuban President Fidel Castro in HavanaFormer Cuban President Fidel Castro is accusing detractors of U.S. President Barack Obama of racism.

In an essay on state-run Web site cubadebate.com Monday, Mr. Castro said the "extreme right hates" Mr. Obama for being African-American and will do "everything possible" to block his agenda.

He said Mr. Obama inherited the problems of former U.S. President George W. Bush, but is trying to, in his words, "improve the deteriorated image" of the United States.

Mr. Castro cited as examples President Obama's efforts on health care, climate change, immigration reform, reviving the economy and eliminating tax havens. But he said none of those initiatives will change the capitalist U.S. system, as some opposition Republicans have charged.

He also criticized President Obama's increased efforts in Afghanistan, saying taking troops from Iraq and sending them to fight the Taliban is a "mistake."

Mr. Castro said Afghanistan is where the Soviet Union failed, and that the European allies of the United States are increasingly resistant to having more troops die in the war, or, as he put it; resistant to "spilling the blood of their soldiers."

Mr. Castro frequently comments on U.S. policy and international affairs on the state Web site. The latest remarks come as the U.S. governor from the southwestern state of New Mexico, Bill Richardson, is on a trade visit to Cuba.

Mr. Obama has talked about the possibility of re-establishing relations with communist Cuba, after 50 years of hostilities and a decades-long trade embargo - but only if there are major changes in the Cuban government's human rights policy.

Some information for this report was provided by AP.