Cuba is far from seeing a McDonald's or Starbucks open anytime soon, but the diplomatic thaw with the United States is bringing more visitors to the sweltering island.

While the US embargo against Havana still forbids regular tourism, a growing number of US citizens have flocked to the Caribbean destination under easier-to-get special permits.

Excitement about visiting Cuba has grown since US President Barack Obama and his Cuban counterpart, Raul Castro, made the surprise announcement in December that they would restore diplomatic relations.

While the countries have yet to reopen embassies, Obama and Castro will take a historic new step should they meet at the Summit of the Americans in Panama this week.

Cuba has fascinated tourists from around the world because it appears frozen in time, with its aging buildings and old Buicks from the 1950s that are still around as the embargo prohibits imports of US cars.

US-based companies that organize visits say demand has soared this year. In January, Obama made travel under the special categories a bit easier by no longer requiring that US visitors ask for permission before getting on a plane to Cuba.

"The measures ... that we have softly implemented have achieved what we wanted, which is to increase contact among US and Cuban citizens," Ricardo Zuniga, Obama's top Latin America adviser, told reporters in Washington on Tuesday.

Recalling that Obama urged Congress to lift the embargo in January, he said, "We think that it's through dialogue and contact we will be able to see an improvement in the conditions of Cuban citizens."

Tom Popper, president of tour company InsightCuba, said his firm sends 3,000 to 5,000 Americans to Cuba per year, but he hopes to double or even triple that figure this year.

"Cuba and traveling to Cuba is on the mind of most Americans," said Popper, whose New York-based company organized visits last year by Major League Baseball legends Ken Griffey Jr. and Barry Larkin.

Alina Fernandez, president of Cuba Travel USA, said interest has quadrupled for the next high season, which is from December to May.

About 100,000 Americans visit Cuba every year, a figure that could increase by 30 to 50 percent this year, Fernandez said. The problem, she said, is that the country lacks the hotel capacity for a major tourism influx.

Warming US-Cuba ties has raised hopes among Cubans that the rapprochement will be coupled with renewed business, bringing more money to a country where people make $20 per month on average.

"The American tourist is the best in the world. Americans are splendid when it comes to tipping. We've had many here in the past months," said Victor Hugo Felipe, owner of the Kilometro 0 restaurant, one of the private paladares that have opened in recent years.