HAVANA, July 20 -- After 54 years of confrontation and animosity, Cuba and the United States reopened embassy in each other's capital on Monday.

However upbeat they may appear on the occasion, it is clear the pair still face an uphill task to mend their deeply damaged mutual trust.

Havana still appears not fully convinced of Washington's sincerity to repair the ties, and for some very powerful reasons.

Speaking on Monday in Washington, Cuban Foreign Minister Bruno Rodriguez said the U.S. craving for domination remained a threat and its "insistence on obsolete and unjust goals...will neither legitimize them or be good for the national interest of the United States or its citizens."

On July 15, less than a week before the reopening of the embassies, President Raul Castro warned that the renewal of the diplomatic ties does not equal to the normalization of the Cuba-U.S. relationship.

Addressing the parliament, he said bilateral ties would not be normal until the United States returns the territory in Guantanamo, stop illegal radio and television broadcasts to Cuba, and call off programs aimed at inciting anti-government movements on the island.

Castro's caution is as evident as it is understandable. For all the soothing words coming from Washington, few of Cuba's concerns have been addressed.

The decades-old blockade has not been lifted, the "wet foot, dry foot" immigration policy remains in place, the U.S. naval base in Guantanamo remains open, and U.S.-backed media outlets are still airing anti-Havana programs.

And while U.S. President Barack Obama is toiling to make the restoration of the U.S.-Cuba ties a lasting legacy of his presidency, he has faced withering contempt from Republican presidential hopefuls on the matter.

Mario Rubio, a Republican senator from Florida and son of Cuban immigrants, has said he would reverse these advances and put Cuba back on the list of sponsors of terrorism, if he is elected president.

International pressure has been mounting for years on the U.S. side to lift the blockade against Cuba and there would be massive protests if a future U.S. president should seek to reverse the decision.

In recent years, Cuba has been making forays into expanding its diplomatic presence across the globe, welcoming leaders from France, Germany, Russia, and the European Union.

"We still do not know what the form this new diplomatic process will take. It will require very intense negotiations since the United States is pushing for a political and economic opening-up in Cuba," said Mario Torrico, a professor at the Latin American Social Sciences Academy in Mexico City.

While July 20, 2015 will go down in history marking a jubilant record for the Cuba-U.S. relations, one thing is for certain: it will take quite a while before the two former adversaries rebuild trust.