– With embassies opening in each country, it might seem that Cuba and the United States are ready to do business with each other.

But there are still many barriers. Not only is a trade embargo still in effect, but businesses also are proceeding slowly when it comes to taking advantage of the limited commercial opening outlined by President Obama as part of the U.S. rapprochement with Cuba.

Among the most visible deals to date are Florida-based Stonegate Bank’s announcement last month that it had signed a correspondent banking agreement with Cuba’s Banco Internacional de Comercio — a move that should make it easier to pay for transactions — and Airbnb’s Cuban launch. It now offers more than 2,000 listings in casas particulares — private homes that rent rooms to travelers.

Yet to materialize are any major deals in agriculture or telecommunications. U.S. rules announced in January allow American companies to sell telecommunications and computer equipment and even partner with the Cuban government in ventures to improve access to the Internet and telecommunications.

Even though Cuba has shortages of many building supplies and the new U.S. rules allow shipments of construction materials and equipment to Cuba’s budding private sector, there have been no announcements by major companies that they’re sending enough supplies to paint Havana or are shipping cement mix.

Cuba is a new frontier.

Because there hasn’t been a semblance of a normal business relationship in more than half a century, when the United States wrote its new rules of business engagement with Cuba earlier this year, it was dealing more with the theoretical than real world. Also, the rules were written hurriedly.

Roberta Jacobson, assistant secretary of state for Western Hemisphere affairs, calls the new rules “a work in progress.”

“Cubans are getting used to it; our business people are getting used to it,” she said. “We are going to tweak. We may not have written them right.”

During a White House briefing last week with business people and academics who have been supportive of the normalization process, briefers said that a revision and clarification of some banking and travel rules would come shortly. They also asked business executives to keep feedback coming on evolving rules.

Florida-based Stonegate is the first U.S. bank to engage with Cuba under the regulations that came out in January.

But banks in general are very nervous about Cuba, said Ted Piccone, a senior fellow at the Brookings Institution. “Part of it is the banking culture is very conservative, but the banks also have seen that they can be heavily penalized if they don’t abide by the letter of the law.”

Meanwhile, as U.S. business pioneers try to strike deals, they must also contend with a Cuban system that doesn’t necessarily mesh with U.S. business practices, limited Internet service, and a Cuban bureaucracy that often seems more interested in going slow than expediting business.

Beyond the sluggish bureaucracy, the government also is testing the shifting currents with caution.

Carlos Alzugaray, a retired Cuban diplomat, points out there are reasons the government wants to go slow and not risk losing political control by allowing too swift an economic transformation or rapprochement with the U.S.

Cuban leader Raul Castro, he said, has undertaken three processes of change at once: economic reform, a new relationship with the U.S., and a generational shift in political power; he retires in 2018.

All carry a degree of risk that could derail the government’s goal of “prosperous and sustainable socialism.”

U.S. companies, such as Google and Twitter, have made overtures to Cuba and a few minor telecom ventures have been inked, but there hasn’t been much response from Cuba on that front.

To help companies try to overcome some of the obstacles in entering the Cuban market, Burson-Marsteller, a public relations firm, recently launched a Cuba consultancy team that will advise clients on matters such as positioning themselves in the Cuban market, how they should enter it, how to present their corporate presence in Cuba and how to effectively communicate to various stakeholders about their Cuba business.

For companies and industries that consider Cuba a longer term play when the embargo is lifted, Burson-Marsteller will advise them on an advocacy role to help bring about policy changes, said Ramiro Prudencio, the company’s Latin America president and chief executive.

Companies that want to do business in Cuba, he said, must be cognizant of whether their venture is in sync with government development plans and offers social and economic benefits to the Cuban people.

“I think that for most companies, Cuba needs to be a long-term play — unless they’re in very specific industries,” he said. But travel and tourism will present “almost immediate opportunities.”