The U.S. Department of Justice on Thursday charged Venezuelan President Nicolás Maduro and 14 current and former officials with money laundering and other charges in an alleged narco-terrorism conspiracy to "flood" the United States with cocaine.

In a livestreamed press conference, U.S. Attorney General William Barr said that Maduro, and other political and military leaders across the Venezuelan government, had worked with a dissident group of rebel fighters to provide safe passage through its airspace in order to move between 200 and 250 metric tons of the drug to locations in North America.

The indictments, in Manhattan, Miami and Washington, D.C., were the result of a decadelong investigation of Venezuela's support for the Fuerzas Armadas Revolucionarias de Colombia, or FARC, a guerrilla movement with deep ties to the international drug trade, and described widespread "criminality and corruption" in the highest levels of Venezuela's government.

Geoffrey Berman, the U.S. Attorney for the Southern District of New York, said the scheme had been operating for more than two decades and represented a deliberate attempt to "flood the United States with cocaine."

The move was seen as a largely unprecedented action against the leader of a foreign country, though the United States government does not recognize Maduro as the legitimate president of Venezuela.

Maduro was charged in the Manhattan federal court with narco-terrorism conspiracy, conspiracy to import cocaine and weapons offenses, offenses that carry a minimum of 50 years and a potential life sentence.

The indictments announced Thursday also targeted the chief justice of Venezuela's supreme court, Maikel Jose Moreno Perez, leaders of the National Constituent Assembly and top officials in the country's military leadership.

The U.S. Department of State is offering millions of dollars in rewards for the capture and conviction of Maduro and his co-defendants, officials said.

"The Venezuelan regime, once led by Nicolás Maduro Moros, remains plagued by criminality and corruption," Barr said in a statement announcing the charges.

"Today's announcement is focused on rooting out the extensive corruption within the Venezuelan government—a system constructed and controlled to enrich those at the highest levels of the government," Barr said. "The United States will not allow these corrupt Venezuelan officials to use the U.S. banking system to move their illicit proceeds from South America nor further their criminal schemes."

According to the indictments, Maduro and his regime gave safe haven to a group of about 2,500 FARC members who have refused to acknowledge a 2016 peace deal, which aimed to end decades of fighting in Columbia. The group had since taken up on the Columbia-Venezuela border, where it continues to carry out its armed insurgency and drug-trafficking operations.

Officials alleged that Maduro and his regime negotiated drug sales and provided cover for the airplanes and boats used to ship cocaine to the U.S. Barr said that one "air bridge" between the Venezuelan state of Zulia had expanded more than five fold in the four years since it was established in 2016. 

Maduro was alleged to have negotiated multiton shipments of FARC-produced cocaine through his effective control of the "Cartel of the Suns," which is headed by high-ranking Venezuelan military officers and is deeply involved in the international drug trade. Officials said that Maduro directed the cartel to provide military-grade weapons to the FARC and coordinated Venezuela's foreign affairs with Honduras and other countries to facilitate large-scale drug-trafficking operations.

Prosecutors in Miami and Washington, D.C., meanwhile, simultaneously unsealed charges against Perez and Venezuela's defense minister, Vladimir Padrino Lopez.

Padrino Lopez, who holds the rank of general in the Venezuelan armed forces, was accused in the U.S. District Court for the District of Columbia with accepting bribes from drug traffickers, and "on numerous occasions" had authorized the Venezuelan military to shoot down other planes that were suspected to be moving cocaine to countries in Central America.

The indictment in the Southern District of Florida alleged that Moreno Perez had taken tens of millions of dollars in bribes to fix criminal and civil cases in Venezuela and authorized illegal money transfers, which he later spent on luxury purchases in the Miami area. 

"An independent judiciary is supposed to be the last line of defense against the powerful and corrupt," Miami U.S. Attorney Ariana Fajardo Orshan said Thursday. "The charges against Chief Justice Moreno demonstrate that the last line of defense in Venezuela has crumbled, creating a system without rule of law, and without justice."

U.S. officials have to date seized more than $45o million from defendants connected with the alleged wrongdoing, and "we are just getting started, she said.

The indictments came as the Trump administration steps up its efforts to unseat Maduro as the authoritarian leader of Venezuela and replace him with the country's opposition leader, Juan Guaido.

The criminal cases against Maduro and his regime were the first to target a sitting head of state since federal prosecutors in Miami charged the former Panamanian ruler Manuel Noriega in 1988 with drug trafficking, racketeering and money laundering. Noriega was convicted in 1992 and was sentenced to 40 years in a Miami federal prison, where he died in 2017.

Asked whether he expected Maduro to ever see the inside of a U.S. courtroom, Barr said he would "explore all options" for bringing him into U.S. custody.

"Hopefully, the Venezuelan people will see what's going on and will eventually regain control of their country," he said.