Venezuelan President Nicolas Maduro on Thursday pleaded against a "crazy war" as an escalating US military campaign sent tensions soaring.

Maduro's comment came after US President Donald Trump said he had authorized covert action against the South American nation amid a military campaign targeting what Washington says are drug traffickers in the Caribbean and Pacific.

"Yes peace, yes peace forever, peace forever. No crazy war, please!" Maduro said in English in a meeting with unions aligned with the leftist leader.

The United States has deployed stealth warplanes and navy ships as part of what it calls anti-narcotics efforts, but has yet to release evidence that its targets -- eight boats and a semi-submersible -- were smuggling drugs.

Speaking to reporters Thursday, Trump again denied that he had sent B-1B bombers to Venezuela, but said "we're not happy with them. They've emptied their prisons into our country."

The president said "we're not going to necessarily ask for a declaration of war" from Congress, which has the constitutional power to do so.

"We're just going to kill people who come into our country." The US strikes, which began on September 2, have killed at least 37 people, according to an AFP tally based on US figures.

An overnight US strike on an alleged drug-smuggling boat operated by a Venezuelan gang killed six people in the Caribbean Sea, Defense Secretary Pete Hegseth said yesterday.

Regional tensions have flared as a result of the campaign, with Maduro accusing Washington of seeking regime change.

Late Thursday, the government in Trinidad and Tobago -- located just off Venezuela's coast -- announced that a US warship would dock in its capital from October 26-30.