US President Barack Obama announced a deal ­on Wednesday to restore ­diplomatic ties with Cuba, ­describing it as an "­historic step forward" that must be followed by an end to the decades-old US embargo.

"Later this summer, Secretary John Kerry will travel to Havana formally to proudly raise the American flag over our ­embassy once more," Obama said.

Cuba's President Raul ­Castro confirmed in a letter to Obama on Wednesday that ­Washington and Havana will reopen ­embassies as early as July 20.

"I am pleased to address this letter to you to confirm that Cuba has decided to re-­establish diplomatic relations with the United States and open ­permanent diplomatic missions in our respective countries, on July 20, 2015," the missive says.

A separate Cuban government statement said Foreign Minister Bruno Rodriguez would lead a delegation at the reopening of the Cuban ­Embassy in Washington.

The agreement comes alongside months of talks with Cuba after the leaders of the two countries agreed in ­December to begin warming relations.

Diplomatic ties have been frozen since 1961.

From the Bay of Pigs invasion to the Cuban Missile Crisis, antagonism across the narrow Straits of Florida often threatened to turn the Cold War hot.

Both countries are ­currently represented by "interest sections" and US and Cuban ­diplomats are not allowed to go outside of Havana and ­Washington without official authorization from their host countries.

It was Castro and Obama who agreed in December to start formal talks over restoring relations, after months of secret talks between aides.

The pair held a historic meeting in Panama in April - the first sit-down between US and Cuba leaders since 1956.

In May, the US paved the way for further rapprochement by taking Cuba off the list of state sponsors of terrorism.

Havana had vehemently ­protested its 1982 inclusion on the blacklist, which hampered its access to global markets.

Polls show a majority of Americans support Obama's efforts to improve ties.

But the island is still subject to a US trade embargo put in place in 1962.

In the meantime, ­other ­vestiges of ideological animosity are rapidly receding into ­history.

Travel and ­communications restrictions between the two countries have been significantly eased.

An American orchestra and sports team toured the Caribbean island for the first time in decades.

The White House has said that a presidential visit is possible before Obama leaves ­office in 2017.