Demise of Venezuela's Opposition Figure in Detention Called 'Vile' by United States Officials.

The US government has criticized the Venezuelan government over the death of a jailed opposition figure, calling it a "clear indication of the despicable essence" of President Nicolás Maduro's rule.

The political prisoner died in his cell at the El Helicoide prison in Caracas, where he had been incarcerated for in excess of twelve months, as stated by rights groups and political opponents.

The Venezuelan government said that the 56-year-old exhibited signs of a cardiac arrest and was transferred to a medical facility, where he died on Saturday.

Intensifying Rhetoric Between US and Caracas

This new intervention from the United States is part of an growing war of words between the Trump administration and President Maduro, who has claimed Washington of seeking regime change.

In the last several months, the United States has expanded its armed forces deployment in the region and has conducted a number of fatal strikes on boats it says have been used for moving narcotics.

US President Donald Trump has accused Maduro himself of being the chief of one of the region's drug cartels—an allegation the Venezuelan president categorically refutes—and has warned of military action "via a land invasion".

"He had been 'unjustly imprisoned' in a 'facility for mistreatment'," declared the American diplomatic office for the region.

Background of the Arrest

He was taken into custody in that year after being among several dissidents to contest the outcome of that year's presidential election.

Venezuela's government-controlled national electoral body declared Maduro the winner, despite opposition tallies indicating their nominee had been victorious by a landslide.

The electoral process were widely dismissed on the international stage as flawed and unfair, and triggered unrest throughout the country.

The former governor, who governed the island state, was indicted of "promoting hatred" and "terrorism" for questioning Maduro's electoral win.

Reactions from Rights Groups and the Opposition

National advocacy group Foro Penal has voiced worry over deteriorating circumstances for political prisoners in the South American state.

"Another jailed opponent has lost his life in Venezuelan prisons. He had been imprisoned for a twelve months, in solitary confinement," stated Alfredo Romero, the group's head, on a social network.

He added that he had only been granted one visit from his family during the full duration of his incarceration. He added that over a dozen political prisoners have died in the country since 2014.

Opposition groups have also condemned the administration over the death of Díaz.

María Corina Machado, a well-known opposition leader who won this year's Nobel Peace Prize but who remains in concealment to evade arrest, stated that Díaz's death was not an isolated incident.

"Unfortunately, it adds to an disturbing and heartbreaking series of demises of political prisoners held in the aftermath of the post-election crackdown," she said.

The coalition of rivals said that Díaz "passed away unfairly".

Díaz's own political party, Democratic Action (AD), also remembered the ex-leader, noting he had been held without justice without proper legal procedure and had remained in situations "that infringed upon his basic rights".

Broader International Tensions

Frictions between the US and Venezuela have become increasingly strained over what Trump has described as actions to stop the influx of drugs and immigrants into the United States.

• US air strikes on ships in the Caribbean and Pacific have resulted in the deaths of more than 80 persons.
• Trump has claimed Maduro of "emptying his jails and psychiatric facilities" into the US.
• The US has classified two Venezuelan drug cartels as terror groups.

Maduro has conversely claimed the US of using its war on drugs as an justification to depose his socialist government and access Venezuela's enormous oil reserves.

The America has also stationed a significant fleet—its biggest movement in the region in decades—along with many troops.

In a related development, the Venezuelan armed forces allegedly enlisted thousands of troops in one go on the weekend, in answer to what military leaders termed US "aggression".