US President George W. Bush has told Latin Americans they had a "God-given right" to freedom in a sharp attack on Cuba's Fidel Castro and other rivals in the region.
Speaking at a 34-nation summit of leaders across the Americas, President Bush singled out Cuban President Fidel Castro for his toughest condemnation.
"Through our democratic example, we must continue to stand with the brave people of Cuba, who for nearly half a century have endured the tyrannies and repression," President Bush said at the summit's inaugural ceremony.
"Dictatorship has no place in the Americas. We must all work for a rapid, peaceful transition to democracy in Cuba," he said.
In recent years, leftist leaders have been elected in Brazil, Argentina and Venezuela. All three countries have established friendly ties with President Castro, who has held power for 45 years despite US efforts to oust and isolate him.
Washington's support for sometimes brutal governments in Latin America during the Cold War left many distrustful of US leadership and anti-American sentiment surged last year with the war against Iraq.
Mr Bush hopes to win back some friends and isolate his rivals at this summit in the northern Mexican city of Monterrey.
He said firm support for democracy "gives hope and strength to those struggling to preserve their God-given rights" and referred specifically to Venezuela and Haiti, which have both clashed with the United States.
Mr Bush largely ignored Latin America over the past two years as he focused on Iraq, Afghanistan and national security. But he is now seeking support from Hispanic voters for his re-election bid this year.