Cuba's foreign minister called President Barack Obama an "imperial and arrogant" liar on Monday for his conduct at the U.N. climate conference, a reflection of the communist island's increasingly fiery verbal attacks on the U.S. government.

Cuban Vice President Juan Almeida, a revolutionary commander who fought alongside Fidel Castro to bring down a pro-American dictatorship, has died, the government announced.

Cuban President Raul Castro warned the United States and the European Union that the country's socialist political system was non-negotiable, adding he would not "restore capitalism" in Cuba.

The US government has pulled the plug on its electronic news ticker outside its mission in Havana because it was not helping improve long-strained bilateral ties, the State Department said.

Cuba's economy has been hammered by the global credit crisis, US relations have not improved much under President Barack Obama and economic reforms that were supposed to ease life on the island have been slow to come.