Havana ? Leftist intellectuals and human rights activists from around the world pleaded with the United States on Monday not to interfere with Cuba while Fidel Castro recovers from intestinal surgery, and Cuba’s parliament speaker warned the U.S. would face dire consequences if it did.

Many of the 400 signers of the open letter are from Latin America, and numerous Nobel Peace laureates are listed, such as former Archbishop Desmond Tutu of South Africa and activist Rigoberta Menchu of Guatemala.

Announcing the letter at a news conference, leading Cuban writer Roberto Fernandez Retamar said Cubans are convinced that Castro’s handover of power to his younger brother and defense minister, Raul Castro, is only temporary.

Vice President Carlos Lage, in Bogota to attend the inauguration of President Alvaro Uribe for a second term, said Monday that Castro “continues to be coming along favorably and we are sure that he will recover.”

The optimistic assessments have been reinforced by other statements from Fidel Castro’s inner circle and Latin American allies, who say the Cuban leader is recovering well from surgery for internal bleeding.