U.S. President Barack Obama and Cuba's Raul Castro sat down together Saturday in the first formal meeting of the two country's leaders in a half-century, pledging to reach for the kind of peaceful relationship that has eluded their nations for generations.

In a small conference room in a Panama City convention centre, the two sat side by side in a bid to inject fresh momentum into their months-old effort to restore diplomatic ties. Reflecting on the historic nature of the meeting, Obama said he felt it was time to try something new and to engage with both Cuba's government and its people.

"What we have both concluded is that we can disagree with a spirit of respect and civility," Obama said. "And over time, it is possible for us to turn the page and develop a new relationship between our two countries."

Castro said he agreed with everything Obama had said — a stunning statement in and of itself for the Cuban leader. But he added  they had "agreed to disagee" at times. Castro said he had told the Americans that Cuba was willing to discuss issues such as human rights and freedom of the press, maintaining that "everything can be on the table."

"We are disposed to talk about everything — with patience," Castro said in Spanish. "Some things we will agree with, and others we won't."

PANAMA-USA/SUMMIT

U.S. President Barack Obama shakes hands with Cuba's President Raul Castro as they hold a bilateral meeting during the Summit of the Americas in Panama City. The two leaders are seeking to restore ties between the Cold War foes. (Jonathan Ernst/Reuters)

Not since 1958 have a U.S. and Cuban leader convened a substantial meeting; at the time, Dwight Eisenhower was in the White House and Fulgencio Batista in charge in Cuba. But relations quickly entered into a deep freeze amid the Cold War, and the U.S. spent decades trying to either isolate or actively overthrow the Cuban government.

In a stroke of coincidence, Eisenhower's meeting with Batista in 1958 also took place in Panama, imbuing Saturday's session between Obama and Castro with a sense of having come full circle.

The historic gathering played out on the sidelines of the Summit of the Americas, which this year included Cuba for the first time.

At the start of their hour-long meeting, Obama acknowledged that Cuba, too, would continue raising concerns about U.S. policies — earning a friendly smirk from Castro. Obama described the sit-down later as "candid and fruitful" and said he and Castro were able to speak about their differences in a productive way.

Raw passions

Nevertheless, raw passions were on vivid display earlier in the day when Castro, in a meandering, nearly hour-long speech to the summit, ran through an exhaustive history of perceived Cuban grievances against the U.S. dating back more than a century.

Then, in an abrupt about face, he apologized for letting his emotions get the best of him. He said many U.S. presidents were at fault for that troubled history — but that Obama isn't one of them.

"I have told President Obama that I get very emotional talking about the revolution," Castro said through a translator, noting that Obama wasn't even born when the U.S. began sanctioning the island nation. "I apologize to him because President Obama had no responsibility for this."

Obama agreed.

"The Cold War has been over for a long time," he said. "And I'm not interested in having battles frankly that started before I was born."

Flurry of diplomacy

The flurry of diplomacy kicked off Wednesday when Obama and Castro spoke by phone — only the second known call between U.S. and Cuban presidents in decades. It continued Friday evening when Obama and Castro traded handshakes and small talk at the summit's opening ceremonies, setting social media abuzz with photos and cellphone video.

'We are disposed to talk about everything — with patience.' - Cuban President Raul Cast

Obama and Castro sent shockwaves throughout the hemisphere in December when they announced the plan for rapprochement, and their envoys have spent the ensuing months working through thorny issues such as sanctions, the re-opening of embassies and the island nation's place on the U.S. list of state sponsors of terrorism.

Although earlier in the week Obama suggested a decision to remove Cuba from the list was imminent, he declined to take that step Saturday, citing the need to study a recently completed State Department review. Lawmakers briefed on that review have said it resulted in a recommendation that Cuba be delisted.

Yet Obama's delay in delisting Cuba comes as the U.S. seeks concessions of its own — namely, the easing of restrictions on freedom of movement for American diplomats in Havana and better human rights protections. Obama met with Cuban dissidents Friday at a civil society forum, and on Saturday he said the U.S. would continue pressing Cuba on issues like democracy and human rights.

"We have very different views about how society should be organized," Obama told reporters just before returning to Washington.

A successful détente would form a cornerstone of Obama's foreign policy legacy. But it's an endeavor he can't undertake alone: Only Congress can fully lift the onerous U.S. sanctions regime on Cuba and there are deep pockets of opposition in the U.S. to taking that step.

As he sat down with the American president, Castro observed that nothing is truly static. Today's profound disagreements could turn into areas of consensus tomorrow.

"The pace of life at the present moment in the world," he said, "it's very fast."