MIAMI (AFP)--Major U.S. cruise companies suspended visits to Mexican ports Tuesday due to the swine flu outbreak.

As the virus continued to spread, Royal Caribbean, Carnival and the Norwegian Cruise Line - who transport thousands of holiday makers daily around the Caribbean - announced the preventative move.

"Royal Caribbean Cruises Ltd. (RCL) today announced it is temporarily suspending its port calls in Mexico," the firm said in a statement.

"The decision was made in an abundance of caution, and allows additional time to better understand the full impact of the swine flu."

Royal Caribbean says it has four cruise ships that regularly stop at Mexican ports, while two additional ships scheduled to make upcoming Mexican port calls have been repositioned.

The Miami-based Norwegian Cruise Line Ltd. also canceled scheduled stops by the "Norwegian Pearl" to Mexican ports on April 28 and May 1. After that there were no scheduled stops at Mexican ports until late September, the cruise line said.

Carnival Corp. (CCL) announced it canceled Mexico stops for three of its ships.