Iran, Venezuela and other states opposed to US policy sought to forge a common front at a Non-Aligned summit in Havana that Cuban leader Fidel Castro was too ill to chair.
The anti-US drive could displease other summit countries such as India and Pakistan who have forged closer relationships with Washington since the September 11th, 2001 attacks.
The question of whether Mr Castro would make his first public appearance since undergoing emergency surgery for intestinal bleeding in late July and ceding power temporarily to his brother Raul Castro loomed over the summit.
State television showed the 80-year-old greeting friend and ally Hugo Chavez, president of Venezuela, fueling talk that he might make a dramatic entrance.
Foreign Minister Felipe Perez Roque told delegates yesterday that Mr Castro's health was "improving continuously" but said "the doctors have insisted that he continue resting and thus he will not lead the Cuban delegation at the summit."
In his absence, Raul Castro chaired the meeting in a rare appearance for one of Cuba's most powerful but least visible figures. But he was often upstaged by Mr Chavez, whose banters and controversial speeches appeared to show him as Fidel Castro's heir apparent.
More than 40 heads of state and government and leaders from countries including North Korea are due to debate a document that backs Iran's right to nuclear technology and another sharply critical of Israel's recent war in Lebanon.
Leaders avoided most of those topics, using their speeches to salute the movement and press for greater cooperation between non-Western nations.
Iranian President Mahmoud Ahmadinejad praised Cuba's "outstanding role ... in advancing the objectives of our movement, the liberation struggle and the fight against imperialism."
"There is a need to strengthen or revitalize our movement more than ever," he said, in a speech that did not mention Tehran's stand-off with the West over its nuclear policy.