The US state of Florida last week passed a law banning researchers at state universities from having any contact with countries the US State Department deems a 'sponsor of terrorism'.
The law will come into force on 1 July.
The federal government currently allows scholars to carry out studies in Cuba, Iran, Iraq, Libya, North Korea and Sudan if they obtain a government licence.
But the new law will stop all of Florida's research in these countries by making it illegal for scientists at state-funded institutes to travel to them.
A number of academics in Florida say the law will impede efforts to learn about Cuba's agriculture, ecology and marine environment, which all have potentially significant effects on Florida's economy.
For example, with Cuba planning offshore oil exploration, research exchanges are seen as vital because of possible spillages.
Some scientists in Florida favour the ban, but those opposed to it are backing a plan by the American Civil Liberties Union to challenge the law in court.