华盛顿大使馆古巴国旗飘扬

US Secretary of State John Kerry has hailed a new beginning after a ceremony marked the reopening of the Cuban Embassy in Washington DC.

The Cuban flag was in the US capital for the first time in more than half a century.  Many say it is a milestone, as the two former cold-war foes continue to build diplomatic relations.

The two nations—narrowly separated by waters, but greatly divided by ideologies—are coming together for the first time in more than half a century.

"We have made it here today thanks to the firm and wise leadership of Fidel Castro Ruz, the historic leader of the Cuban Revolution, whose ideas we will always revere with loyalty. We now recall his presence in this city, in April of 1959, with the purpose of promoting firm bilateral relations," said Bruno Rodriguez, Cuban foreign minister.

On this hot day, the Cold War, it appears, was to be forgotten.

"I wanted to be a witness to history. It's great this happened during Obama's presidency," said a local resident.

Down the street, another historic event, as the top diplomat in the US welcomed his Cuban counterpart.

The US and Cuba stunned the world back in December, announcing their intentions to normalize relations. But economic sanctions—imposed by the US Congress on the island—will remain in place, for now.

"The president has called on Congress to lift the embargo, as a result of this change today," said Kerry.

Havana is Washington's closest neighboring capital, but decades of mistrust have blocked any cooperation between the two. The opening of the embassies marks another step toward changing that. But a number of issues remain unresolved, so the road ahead is still long.