By Daniel Trotta and Sarah Marsh
HAVANA (Reuters) - Cuba's leftist allies joined a sprawling multitude of Cubans chanting "I am Fidel" at a rally on Tuesday to commemorate Fidel Castro, offering eulogies to the man who built a Communist state on the doorstep of the United States.
Castro died on Friday at age 90, a decade after ceding control to his younger brother Raul Castro, 85.
With Raul Castro at his side, the charismatic Fidel Castro led the bearded rebels who seized power in a 1959 revolution and ruled the island in the face of U.S. opposition that endured until President Barack Obama reversed course in 2014 and set out to restore diplomatic relations.
For many, especially in Latin America and Africa, Castro was a symbol of resistance to imperialism, having ousted a U.S.-backed dictator, and a champion of the poor. Others, including many in the large Cuban exile community in Miami, have condemned him as a tyrant who jailed opponents and ruined the economy through socialism.
Chants of "Viva Fidel!" resounded as tens of thousands massed in Havana's Revolution Square on Tuesday evening to pay homage to Castro. "United, the people will never be defeated!" rang another.
"We and our self-sacrificing, combative and heroic people say to you: Ever onward to victory," Castro said in a tribute to his brother.
Castro embraced his ideological ally, visiting Venezuelan President Nicolas Maduro, as the ceremony got underway.
"They could overcome neither Fidel, nor the people of Cuba nor the dreams and hopes of this great nation," Maduro said in a tribute, chanting a refrain about the iconic revolutionary fending off imperialists that the crowd then finished.
"He fulfilled his mission on this earth," he added. "Few lives have been so complete, so bright. He has left unconquered."
The White House announced on Tuesday that Obama would not send a presidential delegation. Instead, the United States was represented by Jeffrey DeLaurentis, chief diplomat at the U.S. embassy in Havana, and Ben Rhodes, an Obama aide who represented the United States in 18 months of secret talks that led to detente.
That rapprochement is now threatened by U.S. President-elect Donald Trump, who takes office on Jan. 20 and who has spoken of resuming Washington's hard line unless the government makes political changes, the kind of pressure the Castro brothers always fiercely resisted.
DeLaurentis was head of the U.S. interests section in Havana when it was upgraded to an embassy in July 2015 and has been nominated by Obama to be named ambassador. White House spokesman Josh Earnest called Rhodes "the principal interlocutor with the Cuban government from the White House" on normalization.
Many leaders of Latin America's left, including Maduro and Bolivian President Evo Morales, flew in to attend the ceremony in the same space where Castro once delivered rousing, marathon speeches.
African leaders included Zimbabwe's Robert Mugabe and South African President Jacob Zuma, who paid Castro a tribute of his own. The late Nelson Mandela repeatedly thanked Castro for his efforts in helping overturn apartheid in South Africa.
Mugabe, 92, himself a former Marxist guerrilla who has led Zimbabwe as prime minister or president since 1980 despite financial and health crises, praised Fidel Castro's government for having trained thousands of Zimbabwean doctors and teachers.
Few leaders from the world's major powers attended, with many sending second-tier officials instead.
China sent Vice President Li Yuanchao, while Chinese President Xi Jinping visited the Cuban embassy in Beijing to pay his condolences, China's foreign ministry said
Russian President Vladimir Putin has skipped the ceremony but described Castro as a "true friend of Russia." The Kremlin said he held a different view on his legacy to that of Trump, who has called the Cuban leader "a brutal dictator."
The Cuban government, still essentially dedicated to Fidel Castro's political vision despite some economic reforms under Raul Castro, has declared nine days of mourning. That has included a two-day commemoration in Havana, where tens of thousands of Cubans have waited in long lines to pay their respects in Revolution Square.
"It was important for us to say a final goodbye and to tell him he will forever in our hearts," said housewife Ana Gongora, 52, as she queued up earlier on Tuesday to pay her respects. "We will continue the struggle and will carry on with the concept of revolution that he taught us."
Some in tears or wrapped in the Cuban flag, mourners have filed past Castro's favorite portrait of himself, dressed in military fatigues and carrying a rifle. Many state employees and school children came together in groups.
Some in downtown Havana however hoped that the departure of Castro´s imposing presence would pave the way for deeper change, and that Cuba´s government will double down on reforms aimed at opening up the economy.
A caravan carrying Castro's ashes will depart Havana on Wednesday en route to the eastern city of Santiago de Cuba, his final resting place, in a reversal of the journey he took with the rebel army that overthrew Fulgencio Batista in 1959.
(Additional reporting by Nelson Acosta and Ana Isabel Martinez; Editing by Simon Gardner, Richard Chang and Michael Perry)