HAVANA - Cuban and US officials sit down Thursday for a second day of landmark talks in Havana aimed at reopening embassies and restoring ties frozen for decades.

The two sides claimed a good first day on Wednesday despite persistent disagreements over US migration policies, which communist-led Havana says encourages Cubans to flee to nearby Florida.

US assistant secretary of state Roberta Jacobson, the most senior US official to visit Cuba since 1980, will lead the American delegation for the second and last day of talks between the erstwhile Cold War rivals on Thursday.

Jacobson had a working dinner with her Cuban counterparts Wednesday evening.

US President Barack Obama and Cuban leader Raul Castro surprised the world in December when they simultaneously announced plans to normalize relations following months of secret negotiations.

The raising of the US and Cuban flags in each other's capitals would send powerful signals of the new era the two nations want to enter, though no timeline has been given for the reopening of embassies. On the eve of the talks, US Secretary of State John Kerry warned that the two sides still have much to negotiate before the longtime rivals can normalize ties frozen since 1961. "When it is timely, when it is appropriate, I'll look forward to traveling to Cuba in order to formally open an embassy and begin to move forward," Kerry said in Washington. Cuban officials have also downplayed expectations of major breakthroughs this week, stressing that normalizing ties was a long and complex process.

Cuba will be represented by the foreign ministry's US affairs department, Josefina Vidal. The two sides will negotiate how to turn their "interests sections" into fully functioning embassies with ambassadors in Washington and Havana.

The US mission to Cuba, a concrete and glass building along the capital's picturesque seawall, has been a symbol of the countries' animosity since it opened in 1977.

Across the main entrance, the Cuban government built a vast esplanade to hold anti-US rallies. In 2006, then president Fidel Castro ordered 138 flag polls erected to block political message the mission was emitting with a giant display screen.

Now, Washington wants Havana to reaccredit its diplomats; end travel restrictions for them within the island; ease shipments to the US mission; and lift a cap on US personnel.

For its part, the Cuban delegation voiced "deep concerns" over the situation of the interest section in Washington, saying the US embargo has left its consulate without banking services for almost a year.

Arturo Lopez Levy, international affairs professor at New York University, said the talks are important to build trust as they seek new relations in the coming years.

"Although Havana and Washington differ in the objective that they seek in the long term, today they are in the same bed. It doesn't matter that they have different dreams," he said.

Lingering differences were on display on Wednesday, as Cuban and US officials remained at odds over US policies that give Cubans who reach US soil quick access to permanent residency. But the two sides came out positive in Wednesday's first day of talks, welcoming the meeting as productive while vowing to meet again.

Ordinary Cubans want the rapprochement to improve their lives in a country where supermarket shelves often lack basic goods, and people make $20 a month on average.

Obama urged the Congress on Tuesday to end the decades-long embargo against Cuba, which the Castro regime has blamed for the country's economic woes.

The dissident community on the island of 11 million has had a mixed reaction, praising Obama while voicing concern that too much was conceded to the regime.

In Washington, some Cuban-American lawmakers have criticized Obama, saying the administration had given up too much without securing human rights commitments.

"As the administration pursues further engagement with Cuba, I urge you to link the pace of changes in US policy to reciprocal action from the Castro regime," Senator Bob Menendez, a fellow Democrat, said in a letter to Kerry.

A US official said human rights will be on the table, saying it was "very important to us."