US Defence Secretary Robert Gates has expressed concern traffickers trying to get drugs into the United States will begin using routes through the Caribbean.
At a regional security conference in Barbados, Mr Gates emphasised the need to tighten coordination between anti-drug efforts in Latin America, the Caribbean and the US.
He said pressure on Mexican routes was likely to make smugglers shift their efforts.
The United States says about three-quarters of South American cocaine comes through its border with Mexico, entering the country after being smuggled overland through central America.
Caribbean leaders believe the drug trade through the islands is already increasing.
US funding for Caribbean security will rise to $US70 million in 2011 from $US45 million in 2010.