US President Donald Trump has confirmed a report he authorised the CIA to conduct covert operations inside Venezuela, provoking outrage from the South American nation's leader, BBC reported.

US forces have already conducted at least five strikes on suspected drug-carrying boats in the Caribbean in recent weeks, killing 27 people. UN-appointed human rights experts have described the raids as "extrajudicial executions".

Speaking at the White House, Trump said the US "is looking at land" as it considers further strikes on drug cartels in the region, according to BBC.