The talks in Havana focused on restoring diplomatic ties. Photo: Getty Images

The discussions had focused on restoring diplomatic relations but no date was set for the reopening of embassies.

A US official said normalising relations after decades of hostilities would take time.

The Cuban delegation chief said lifting the economic blockade against Cuba was essential.

Josefina Vidal said no date had been set for the next round of discussions.

These were the highest-level talks in decades between the US and Cuba.

The talks followed December's agreement by US President Barack Obama and his Cuban counterpart, Raul Castro, to improve ties.

The head of the US delegation, Assistant Secretary of State for the Western Hemisphere Roberta Jacobson said: "We have to overcome more than 50 years of a relationship that was not based on confidence or trust."

Ms Vidal, her Cuban counterpart, said: "It was a first meeting. This is a process."

She said she expected a new meeting to be scheduled in the coming weeks ahead of April's Summit of the Americas, which President Obama and President Castro are expected to attend.

Analysis: Will Grant, BBC News, Havana

It was a businesslike response after the talks from Assistant Secretary of State Roberta Jacobson. She employed much less of the optimistic rhetoric about the thaw that the Democratic Party's Congressmen and Senators used when they visited the island earlier this week. Instead the woman leading this historic delegation was more measured and reserved with her comments.

Nevertheless, she defined the conversations as "positive and productive" and said "real and concrete steps" towards re-establishing the long frozen diplomatic ties had been discussed. For example, both sides had apparently agreed that their future relations should be guided by the norms of the Vienna Convention.

But there are still many wrinkles to be ironed out. Josefina Vidal, who led the Cuban delegation at the table, set out one of them from the Cuban government's perspective: "We expressed that the it would be difficult to explain that diplomatic relations have been resumed while Cuba is still unjustly listed as a state sponsor of international terrorism."

There is much to be discussed in future negotiations before embassies can be reopened in their respective capitals or ambassadors named. But if nothing else these talks have shown the political will is there to achieve those goals.

The first day of talks focused on migration.

Ms Jacobson's deputy, Alex Lee, said: "The productive and collaborative nature of today's discussion proves that despite the clear differences that remain between our countries, the United States and Cuba can find opportunities to advance our mutually shared interests."

However, Ms Vidal criticised US migration policies but said Cuba aspired to have a normal relationship with the United States "in the broader sense but also in the area of migration".

On Tuesday, in a speech ahead of the opening of the talks, Mr Obama urged Congress to seize the chance to end the US trade embargo against Cuba.