Jose Ramon Cabanas Rodriguez (above, center) presented his credentials to US President Barack Obama during a ceremony at the White House, the Cuban embassy said in a statement.

"The Cuban ambassador's accreditation to the United States is a further step within the process to normalize relations between both countries," it said.

Cabanas had run Havana's de facto embassy in Washington since 2012, and became charge d'affaires when relations were formally restored in July. He also previously served as Cuba's envoy to Austria, and as a foreign affairs vice minister in the Havana government.

Washington is yet to name its ambassador to Cuba.

Gradual steps

The two nations broke off diplomatic relations in 1961 at the height of the Cold War. After over five decades of mutual hostility, a thaw in ties gained momentum following a meeting between Obama and Cuban President Raul Castro last December.

Cuba and the US officially restored their relations in July. Since then, the two countries have sought to settle a number of contentious issues, including human rights on the island, and claims by US citizens to property confiscated in the aftermath of the Cuban revolution. Havana, meanwhile, is seeking an end to the US embargo and the return of the naval base at Guantanamo Bay.

A US official quoted by Associated Press said the goal was to tackle the biggest differences between the two countries by December 2016, before Obama leaves office.

US Secretary of State John Kerry watches on as officials raise the US flag over the newly reopened embassy in Havana

Stronger business ties

US government sources said Thursday they were drafting sweeping regulations aimed to weaken the trade embargo on Cuba and make it easier for US citizens to travel to the island and do business there.

According to the new rules, expected to be released in the coming days, US companies would be allowed to set up offices in Cuba for the first time in half a century. The regulations would also make it easier for airlines and cruise ships to import technology to improve safety in Cuba; loosen restrictions on software exports; and allow companies to establish subsidiaries with Cuba.

"These are the most comprehensive expansion in US trade and investment regulations with Cuba in decades," said John Kavulich, head of the US-Cuba Trade and Economic Council.

There are also plans to begin regular commercial flights between Cuba and the US and for a "pilot program" allowing Cubans and Americans to send mail directly to one another.

Obama has used his executive powers to relax some US travel and trade restrictions, but the Republican-controlled House of Representatives has stymied his attempts to end the wider embargo.

nm/jil (Reuters, AP)