President Raul Castro has demanded that the United States respect Cuba's communist rule as the two countries work to restore diplomatic ties, and warned that Cuban-American exiles might try to sabotage the rapprochement.

Obama and this week reset Washington's Cold War-era policy on Cuba and the two countries swapped prisoners in a historic deal after 18 months of secret talks.

Castro said he is open to discussing a wide range of issues but that they should also cover the US and he insisted Cuba would not give up its socialist principles.

"In the same way that we have never demanded that the United States change its political system, we will demand respect for ours," Castro told the National Assembly on Saturday.

Castro's speech was a sharp counterpoint to the message US President Barack Obama gave in his year-end news conference the day before.

Obama reiterated that by engaging directly with the Cuban people, Americans are more likely to encourage reform in Cuba's one-party system and centrally planned economy.

US officials will visit Havana in January to start talks on normalising relations and Obama has said his government will push Cuba on issues of human and political rights as they negotiate over the coming months.

Trade embargo

Despite the markedly improved tone in relations, Castro said Cuba faces a "long and difficult struggle" before the US removes a decades-old economic embargo against the Caribbean island, in part because influential Cuban-American exiles will attempt to "sabotage the process".

Inside Story: US and Cuba, foes no more

Obama has pledged to remove economic sanctions against Cuba but he still needs the Republican-controlled Congress to lift the embargo.

Gabriel Elizondo, reporting from the capital, Havana, said there was a real sense of enthusiasm among Cubans for rapprochment with the US and what it could mean in everyday life for people.

"But what Castro and others really want is the complete ending of the embargo altogether," our correspondent said. " That is deeply opposed by some in the US, but the view here is that any opposition is unwarranted." 

Castro confirmed he will take part in a Summit of the Americas in Panama in April, potentially setting up a first meeting with Obama since they shook hands at Nelson Mandela's funeral a year ago.

That brief encounter drew wide attention. Unbeknownst to the world at the time, the US and Cuba were already six month into secret talks set up with the help Pope Francis and the Canadian government.

Source: Al Jazeera and agencies