In this file photo taken on July 28, 2019 Venezuelan President Nicolas Maduro delivers a speech during the closing ceremony of the the Sao Paulo Forum at Miraflores Presidential Palace in Caracas. (FEDERICO PARRA / AFP)

Venezuelan President Nicolas Maduro stood defiant in the face of a US$15 million bounty by the United States to face drug trafficking charges, calling US President Donald Trump a "racist cowboy" and warning that he is ready to fight by whatever means necessary should the US dare to invade.

Maduro's remarks on Thursday night came hours after the US announced sweeping indictments against him and several members of his inner circle for allegedly converting Venezuela into a criminal enterprise at the service of drug traffickers and terrorist groups.

READ MORE: US indicts Venezuela's Maduro, aides on narco-terrorism charges

One indictment by prosecutors in New York accused Maduro and the ruling socialist party leader Diosdado Cabello, head of the Venezuelan constitutional assembly, of conspiring with Colombian rebels and members of the military "to flood the United States with cocaine" and use the drug trade as a "weapon against America".

Donald Trump, you are a miserable human being. You manage international relations like a New York mafia extortion artist you once were as a real estate boss

Nicolas Maduro, Venezuelan president

Maduro said the charges were politically motivated. He said they ignore US ally Colombia's role as the main source of the world's cocaine and his own role in facilitating peace talks between Colombia's government and that country's rebels over the past decade.

"Donald Trump, you are a miserable human being," Maduro railed during his televised address."You manage international relations like a New York mafia extortion artist you once were as a real estate boss.

"If one day the imperialists and Colombian oligarchy dare to touch even a single hair, they will face the Bolivarian fury of an entire nation that will wipe them all out."

Earlier, Venezuela's chief prosecutor opened an investigation against opposition leader Juan Guaido for allegedly plotting a coup with retired army general Cliver Alcala, who, after being named in the US indictments, said he had stockpiled assault weapons in Colombia for a cross-border incursion.

US media reported that the indictment of a head of state was highly unusual, and this action served as an escalation of the Trump administration's campaign to pressure Maduro to step down.

The indictment is also bound to ratchet up tensions with Washington as the spread of the coronavirus threatens Venezuela's health system. Maduro has ordered Venezuelans to stay home in an effort to curb the spread of the virus, which officials say has infected 107 people and claimed its first death on Thursday.

Criminal acts to advance a drug and weapons conspiracy that dates to the start of late Venezuelan leader Hugo Chavez's revolution in 1999 occurred as far afield as Syria, Mexico, Honduras and Iran, the US indictment alleges. US Attorney General William Barr estimated the conspiracy helped smuggle as much as 250 tons of cocaine a year out of South America.

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Meanwhile, the US State Department offered a reward of up to US$15 million for information leading to the arrest or conviction of Maduro.

Serious new phase

The indictment marks a serious new phase against Maduro by Washington at a time when some US officials have privately said Trump is increasingly frustrated with the results of his Venezuela policy, Reuters reported.

In Miami, prosecutors charged Venezuelan Supreme Court Chief Justice Maikel Moreno with laundering in the US at least US$3 million in illegal proceeds from case fixing in Venezuela, including one involving a General Motors factory. He spent much of the money on private aircraft, luxury watches and shopping at Prada, prosecutors allege.

But it is unclear how the move will bring Venezuela any closer to ending a 15-month standoff between Maduro, who has the support of Russia, and the US-backed Guaido. The US has been pursuing a policy of economic sanctions and diplomatic isolation against the Maduro government in support of Guaido.

Maduro has long accused the US "empire" of looking for any excuse to take control of the world's largest oil reserves, likening its plotting to the 1989 invasion of Panama and the removal of general Manuel Noriega to face drug trafficking charges in Florida.