Three Cook Islands-registered ships have been turned back from United States ports for not complying with a new security code.
The registrar of ships, Garth Broadhead, says a cargo ship and a tall ship were denied entry while a cargo vessel was expelled from Martha's Vineyard in Massachusetts.
The Cook Islands News says this follows the introduction of the United Nations International Shipping and Ports Facility security code last week.
The code requires international ships to have a signed certificate from their flag country, stating they they comply with new standards aimed at foiling terrorists.
These include identification documents and security measures such as working alarm systems.
Yachts and small fishing boats which are not involved in trade are excluded from the code.
But, Mr Broadhead is warning all Cook Islands registered vessels, especially fishing boats that sail to international ports like American Samoa, to comply with the code.