Venezuela says it has thwarted what it calls a CIA-linked plot to attack a US warship anchored in Trinidad.
It claims the US would have blamed Venezuela for the attack on the USS Gravely, a guided-missile destroyer, to justify aggression against it.
The allegation comes a day after Venezuela said it had arrested mercenaries it alleged were connected to the US intelligence agency.
Venezuelan Foreign Minister Yvan Gil said in a statement he had advised Trinidad and Tobago of the alleged false-flag operation.
"On our territory a criminal cell financed by the CIA and linked to this covert operation is being dismantled," Mr Gil said.
Interior Minister Diosadado Cabello said at least four suspects had been arrested.
Venezuela, which regularly claims to have arrested US-backed mercenaries, did not give further details about the alleged plot.
[LINK: DW map]The US has already launched several air strikes on vessels in the Caribbean Sea that it alleges were involved in drug trafficking, killing 43 people.
US President Donald Trump said the mounting military campaign in international waters was against alleged drug traffickers in Latin America.
But Venezuela claims the US is working to oust President Nicolás Maduro, who Washington does not recognise as a legitimate leader.
Charles Sturt University terrorism studies lecturer César Álvarez told the ABC earlier in October it was increasingly appearing as though the US was seeking a regime change.
US politicians have speculated about similar motivations.
Democratic senator Jeanne Shaheen said the American people "deserve to know" whether the US government was pursuing a regime change.
US Navy deployed to Caribbean
Mr Trump said recently he had approved covert action in Venezuela and was considering launching operations on Venezuelan territory.
That would be in addition to a US naval deployment in the Caribbean off the coast of Venezuela.
The deployment features seven warships, which will be joined by the world's biggest aircraft carrier, the USS Ford.
On Sunday, the USS Gravely docked in the Port of Spain, the capital of Trinidad and Tobago, for a four-day visit that will include joint training with local defence forces.
Venezuela, which has a coast that comes as close as 11 kilometres to Trinidad, called it a provocation "aimed at provoking a war in the Caribbean".
ABC/AFP