Cuba will be barred from next month's Summit of the Americas at U.S. insistence but Havana's friends Argentina and Brazil are vowing with new resolve to have Havana leaders present at subsequent conferences.

Cuba's exclusion from the April 14-15 Summit of the Americas in Cartagena, Colombia, has split member states, with host Colombia attempting brinkmanship so as not to spoil its own carefully cultivated connections with Cuba's liberalizing economy.

Most Latin American countries see Cuba emerging as the next big commercial opportunity while Cuban President Raul Castro frees up the state's fetters on business and private economic activities. Tens of thousands of Cubans turfed out of government jobs have been told they are free to operate as self-employed entrepreneurs, within certain limits.

Brazil clinched multibillion-dollar deals with Castro when President Dilma Rousseff visited Havana and met with Castro and elder brother Fidel Castro.

The Cartagena summit host, Colombian President Juan Manuel Santos soon followed, to make sure his compliance with the U.S. request to keep Cuba out won't offend Cuba. He flew into Havana and met with the Castro brothers as an insurance against a diplomatic reversal at the summit, analysts said.

In comments this week, Argentine and Brazilian ministers vowed to make sure Cuba's exclusion from the Cartagena summit would be the last such measure against Cuba.

"This has to be the last summit in which Cuba does not participate," said Argentine Foreign Minister Hector Timerman as he appeared with his Brazilian counterpart Antonio Patriota.

The two met in Sao Paolo and declared the presence of Cuba would be necessary at the next gathering so that "finally we have a Summit of the Americas."

The summit is organized by the Organization of American States, which has headquarters in Washington. The U.S. position specifies Cuba cannot participate because it hasn't complied with the OAS charter on democratic principles.

OAS suspended Cuba in 1962 but lifted the suspension in 2009. Cuba has ignored suggestions it can re-enter the organization if it complies with charter requirements to implement democratic reforms.

The U.S. position contrasts with increasing diplomatic and economic activity between Cuba and its Latin American neighbors.

Cuba is under U.S. sanctions, the longest such period of sanctions in history. But trade deals between Cuba and Latin American neighbors have prompted the Communist Party government to move toward economic liberalization. Although Castro's reforms run counter to the Communist Party line, more are to be introduced in the coming months.

Meanwhile, U.S. attitudes toward Cuba appear to be toughening. Florida lawmakers this week passed a measure forbidding local governments from hiring companies that do business with Cuba.

The Miami Herald said the law, which governs contracts worth at least $1 million, appears to be aimed at Odebrecht USA, one of the largest contractors in Miami-Dade County. The company is a subsidiary of a Brazilian conglomerate whose Cuban affiliate is working on a major expansion of the Port of Mariel in Florida.

The law, which also covers companies that work with Syria, is designed to keep taxpayers' money from going to repressive regimes. Cuba and Syria are on a U.S. list of state sponsors of terrorism.

Experts say the law likely will be challenged in court.