The Cuban flag has been raised over the country's newly restored embassy in Washington DC as the US and Cuba resume diplomatic ties frozen for half a century.
An honour guard in white uniforms marched out of the building in the US capital on Monday to hoist the standard watched by a cheering crowd, only hours after the flag was also put in place at the US state Department.
Bruno Rodriguez, Cuban foreign minister, presided over the flag-raising ceremony, just hours after full diplomatic relations with the US were restored at midnight, when an agreement to resume normal ties on July 20 took effect.
About 500 guests, including a 30-member delegation of diplomatic, cultural and other leaders from the Caribbean nation, attended the ceremony at the 16th Street mansion in Washington DC.
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The US was represented at the event by Roberta Jacobson, assistant secretary of state for western hemisphere affairs, and Jeffrey DeLaurentis, the chief of the US interests section in Havana who will now become charge d'affaires.
Earlier, without ceremony, the Cuban flag was hung in the lobby of the state department alongside those of other countries with which the US has diplomatic ties.
The US and Cuba severed diplomatic relations in 1961 and since the 1970s had been represented in each other's capitals by limited-service interests sections.
Kerry later said the US aimed to live "as good neighbours" with Cuba, but cautioned that the road to full relations remained "long and complex".
Meeting in Havana
Speaking in Spanish alongside Rodriguez just hours after diplomatic ties were restored, Kerry said the US "welcomes this new beginning in its relationship with the people and government of Cuba".
But switching back to English, he said the move did "not signify an end to the many differences that still separate our governments". Kerry will travel to Havana August 14 to preside over a flag-raising ceremony at the US embassy there.
Though normalisation has taken centre-stage in the US-Cuba relationship, there remains a deep ideological gulf between the nations and many issues still to resolve.
Among them disputes over mutual claims for economic reparations, Cuba's insistence on the end of the 53-year-old trade embargo and US calls for Cuba to improve on human rights and democracy.
Some US legislators, including several prominent Republican presidential candidates, have pledged not to repeal the embargo and pledged to roll back Obama's moves on Cuba.
Monday's events cap a remarkable change of course in US policy towards the communist island under President Barack Obama, who had sought rapprochement with Cuba since he first took office and has progressively loosened restrictions on travel and remittances to the island.
Shortly after midnight, the Cuban interests section in Washington DC switched its Twitter account to say "embassy".
In Havana, the US interests section uploaded a new profile pictures to its Facebook and Twitter accounts that says US EMBASSY CUBA.
Conrad Tribble, the US deputy chief of mission in Havana, said on Twitter: "Just made first phone call to State Dept. Ops Center from United States Embassy Havana ever. It didn't exist in Jan 1961."
Obama's efforts at engagement were frustrated for years by Cuba's imprisonment of Alan Gross, a US Agency for International Development contractor, on espionage charges.
But months of secret negotiations led in December to Gross' release, along with a number of political prisoners in Cuba and the remaining members of a Cuban spy ring jailed in the US.
Diplomatic game changer
Al Jazeera's Latin America Editor Lucia Newman, reporting from Havana, described the latest developments as "a long-awaited game changer".
"This week's renewal of diplomatic relations does not erase political differences but psychologically it raises the curtain for most Cubans," she said.
On December 17, Obama and Cuban President Raul Castro announced they would resume full diplomatic relations.
Declaring the longstanding policy a failure that had not achieved any of its intended results, Obama declared that the US could not keep doing the same thing and expect a change.
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Thus, he said work would begin apace on normalisation.
That process dragged on until the US removed Cuba from its list of state sponsors of terrorism in late May and then bogged down over issues of US diplomats' access to ordinary Cubans.
On July 1, however, the issues were resolved and the US and Cuba exchanged diplomatic notes agreeing that the date for the restoration of full relations would be July 20.
Larry Luxner, the editor of the Washington Diplomat, said it was clear from recent developments in the US relationship with Iran and Cuba that Obama wanted to leave a legacy of improved diplomatic ties.
"It's a new approach by the White House of wanting to correct the wrongs of the past," he told Al Jazeera.
FIELD NOTES FROM OUR CORRESPONDENT
|Al Jazeera's Latin America Editor Lucia Newman
HAVANA, CUBA - Staff at the newly inaugurated US embassy in Havana showed up for work on Monday carrying small American flags. Even local Cuban staff were carrying them.
A woman who went in to request a visa to the US told us that there is new, more comfortable furniture for those who wait and that the American staff "is more friendly" than before, when they denied her a visa.
Several American citizens who went to the embassy held up their passports and took pictures outside with Cubans to mark the first day of the embassy opening.
The US flag has not been hoisted. That will wait for John Kerry, US secretary of state, when he comes to Havana for the ceremonial opening some time in August, according to US officials.
Cubans are very excited. State TV broadcast the Cuban embassy opening in Washington DC live, calling Monday a historic day for Cuba and Latin America.
"I thought I would never live to see this day," said a tearful Magali Perez , who was 19 years old when the US and Cuba broke diplomatic ties.
Source: Al Jazeera and agencies