Tampa, Florida: Tropical Storm Isaac swept over eastern Cuba on Sunday, bringing heavy rains and strong winds a day after hitting Haiti. It was expected to next head toward the Florida Keys, where it was expected to strike at or near hurricane strength on Sunday.

The storm left six dead in Haiti, still recovering from a 2010 earthquake, and at least three missing in the Dominican Republic after battering their shared island of Hispaniola on Saturday.

Undaunted by Mother Nature, Republicans descended on Florida as Mitt Romney’s team worked Sundays to cram four days of events into three after the threat of Tropical Storm Isaac forced the soon-to-be nominee to cut short his national convention.

Romney is making final preparations for the Thursday speech with which he will accept his party’s presidential nomination.

“The safety of those in Isaac’s path is of the utmost importance,” Romney tweeted after Republican officials announced they had called off Monday’s convention proceedings.

Because of possible storm surges and flooding Isaac could bring, convention organisers said they were making contingency plans to move delegates who have been booked into beachfront hotels to other locations if necessary. They indicated the schedule shift also was meant to prevent overburdening emergency response personnel at the height of the storm.

The GOP made the announcement late Saturday, saying that while the convention would officially be gavelled into session on Monday as scheduled, events would be postponed until Tuesday.

Convention spokesman James Davis said organisers were closely monitoring the storm’s path but planned to rely on emergency management officials to guide decisions on whether to relocate delegates at waterfront hotels. So far, none have been moved nor had officials received word of major problems for inbound delegates.

Davis said the GOP’s advice to delegates was “if your travel plans have not been interrupted and they’re set, we recommend you come on down”.

With Isaac boring down on the coast, President Barack Obama, who had been at Camp David presidential retreat in Maryland, dispatched the Federal Emergency Management Agency to establish a command centre and move more resources into the state. Vice-President Joe Biden scrapped a planned campaign trip into Florida that was to counter the start of the GOP convention.