US and Cuban negotiators launch a second round of historic talks on Friday aimed at overcoming half a century of enmity and restoring full diplomatic ties.
After an initial meeting in Havana in January which ended with little apparent breakthrough, the teams were to meet at the State Department -- the hub of US global diplomacy.
The hope is that within the coming months both nations will agree to reopen embassies in each other's capitals and appoint fully-fledged ambassadors. Currently they operate with so-called interests sections in Havana and Washington.
US President Barack Obama is due to attend the Summit of the Americas in Panama on April 10-11, which Cuba will also attend for the first time.
And observers believe both nations, long mired in tension stemming from the Cold War, are keen to relaunch full diplomatic relations around that date.
But after more than five decades of hostility and suspicion, steep obstacles remain to renewing diplomatic ties.
This is seen as the first step towards a full normalization of relations between the United States and the communist-run Caribbean island which has been governed for five decades by revolutionary leader Fidel Castro and his brother, now President Raul Castro.
Ahead of the talks, both sides staked out their differences.
Cuban officials demanded that as a preliminary step Havana be stripped of its US designation as a state sponsor of terrorism -- a label which has stalked the island since 1982, and which among other sanctions has complicated access to the global banking system.
Washington, however, has insisted that its ongoing review of the terror blacklisting should not be linked to the restoration of diplomatic ties.
In return, the US has insisted that its diplomats and embassy be granted full powers under the Vienna Convention governing global diplomatic relations to operate freely, including meeting with Cuban dissidents.
The US team will be led by the Assistant Secretary for the Western Hemisphere, Roberta Jacobson, who last month became the highest-ranking US official to visit Cuba in 35 years.
She will be sitting across the table from Cuban negotiator Josefina Vidal.
- 'Rolling up sleeves' -
"I certainly think that our presidents and my secretary would be delighted if we could have everything worked out in time for the Summit of the Americas," a senior State Department official told reporters ahead of Friday's talks.
"But that depends a lot on how our counterparts come to the table prepared to get things done and whether they are comfortable with the things we need in order to run an embassy the way we do in other places around the world."
Friday's talks may be a "little bit disappointingly workman-like in their nature this time. But this is where we roll up our sleeves as diplomats and sit down at the table and make sure that we hammer out all of the details out to get embassies up and running."
Restoring diplomatic ties "doesn’t take very long if we get agreement on things," the official added.
Cuban Deputy Foreign Minister Gustavo Machin called for his country to be removed from the terror blacklist saying it would "be a contradiction" if Havana were to remain on the list while enjoying diplomatic ties with Washington.
But the State Department official said that while Washington was "moving forward on the review of Cuba on that list as quickly as we can ... we don’t think that that should be linked to the restoration of diplomatic relations."
"It would be very easy to restore diplomatic relations if they would not link those two things," the official added.
Obama, who in a surprise December agreement said he had agreed to seek normal ties, has called on the US Congress to lift the decades-old biting economic embargo of Cuba.
But some lawmakers -- as well as parts of the Cuban dissident community -- remain wary of the diplomatic demarche, arguing Obama has failed to secure guarantees about progress on human rights.
One of the aims of Friday's meeting is to set a date for the first ever US-Cuba discussion on human rights.
Although no date has been set "it will be the first time that we would be able to sit down with the government directly and have an in-depth conversation about our differing perspectives," the State Department official said.