WASHINGTON — Sen. Marco Rubio's effort to block the Obama administration's planned expansion of travel to Cuba has been grounded -- at least for now.

The Florida Republican and Democratic New Jersey Sen. Robert Menendez had hoped to prevent any new flights from U.S. airports to Cuba following the White House announcement last month to ease travel restrictions to the communist island nation.

But the amendment the pair had hoped to attach to a funding bill for the Federal Aviation Administration won't be heard.

The effort drew sharp criticism from the Tampa Area Chamber of Commerce, which backs Tampa International Airport’s bid to host some of the flights. The group sent a letter to Rubio, asking him to withdraw the amendment, which it called "unfair to those businesses and Cuban-Americans who must bear the undue financial burden and inconvenience of having to travel through Miami.

"Tampa International Airport is prepared to take advantage of expanded flight service, but Senator Rubio’s amendment maintains the status quo of Miami’s monopoly on this economic generator," the chamber wrote.

A spokesman for Rubio though, said he “firmly believes” in blocking more travel to Cuba and that the two Cuban American lawmakers will try to push the legislation again.

"If the administration insists on pursuing its flawed policy to expand direct flights with state sponsors of terrorism,' spokesman Alex Burgos said, "Senator Rubio will continue offering this bi-partisan measure to stop it."

Rubio and Menendez teamed up Thursday to grill a State Department official about the changes, which include making it easier for schools, churches and humanitarian groups to visit the island for what is considered “purposeful travel.’

Noting that US contractor Alan Gross may face as much as 20 years in prison for distributing sophisticated satellite equipment to Cuba’s tiny Jewish community, Rubio asked whether the department would issue a warning to Americans traveling to Cuba.

“Are we going to issue an advisory to Americans that are looking to do purposeful travel...that they may also face 20 years in prison if their contact is too purposeful?” Rubio asked.

Arturo Valenzuela, the Assistant Secretary of State for Western Hemisphere Affairs, noted that anyone who travels to Cuba – including some 300,000 Cuban Americans annually – “may take some risk in traveling,” but that the administration believes the increased contact is important. He noted only Gross has been imprisoned, despite years of groups traveling to Cuba.

“If we continue to isolate the Cuban people, we simply play into the hands of the Cuban regime,” he said.

But Menendez questioned how purposeful the travel would be, holding up a flyer that promised travelers dance lessons in salsa, Son, Mambo and Cha Cha Cha -- for $3,000 a person.

Menendez encouraged the agency to stick to "real itineraries" that offer travelers a chance to talk to "real Cubans, not those who are constrained or directed by the government to engage “Being on a beach in Varadero, having a Cuba Libre and smoking a cigar are not to my mind, how we create freedom,” Menendez said.

Valenzuela said the travel allowed under the new regulations will be “purposeful, regulated travel, where individuals and organizations will have to get license in order to go.

“The intent of these changes is because the president feels that we need to move forward much more effectively to engage directly with the Cuban people to encourage their ability to determine their own future,” he said. “I would be extremely surprised if the dance lessons would be any way countenanced by this kind of a program.

Menendez, however, noted the same company operated when such travel was permitted, before the Bush administration tightened sanctions against Cuba in 2004.

The changes would also allow U.S. airports with top-ranked security capabilities to host charter flights to and from Cuba. Currently, only Miami, Los Angeles and New York are allowed to host the flights.

Along with Tampa, airports in Fort Lauderdale, Orlando, Key West and Las Vegas were among those that had been pushing to be allowed to handle some of the U.S.-Cuba charter flights. More than 40 Cuba flights a week now leave from Miami International Airport.