The United States government fears that a powerful Venezuelan lawmaker may have issued an order to kill Florida Senator Marco Rubio (above)

The United States government fears that a powerful Venezuelan lawmaker may have issued an order to kill Florida Senator Marco Rubio, it was reported on Sunday.

Rubio has been assigned a beefed-up security detail in recent weeks after US intelligence reportedly learned that a former Venezuelan military chief, Diosdado Cabello, put out a hit on the Republican senator, according to the Miami Herald.

The Herald emphasizes that the US government has yet to gather information indicating the existence of a concrete plot to assassinate the former presidential candidate.

Nonetheless, the Department of Homeland Security took the precautionary step of bolstering Rubio's security details in both Washington, DC, and his native Miami.

The DHS issued a memo in which it noted that intelligence indicated 'an order to have Senator Rubio assassinated' while cautioning that 'no specific information regarding an assassination plot against Senator Rubio has been garnered thus far.'

The memo goes on to speculate that Cabello may have contacted 'unspecified Mexican nationals' as part of a plan to harm Rubio, though no specific evidence is cited.

Rubio has been assigned a beefed-up security detail in recent weeks after US intelligence reportedly learned that a former Venezuelan military chief, Diosdado Cabello (above), put out a hit on the Republican senator

The government's heightened state of alert was prompted by a back-and-forth Twitter war between Rubio and Cabello.

Rubio has derisively referred to Cabello as 'the Pablo Escobar of Venezuela' due to longstanding suspicions that the Venezuelan lawmaker has engaged in drug trafficking.

Cabello, who is thought by the Americans to maintain control of Venezuela's security forces, fired back at Rubio, calling him 'Narco Rubio'.

He has denied American allegations of drug trafficking.

In recent weeks, observers on Capitol Hill have been struck by the unusually large security presence surrounding Rubio.

Rubio is a vociferous critic of Venezuelan President Nicolas Maduro, the socialist leader of the South American country.

Maduro has tightened his grip on power despite being deeply unpopular due to a failing economy, food and medicinal shortages, and an election of a new legislative body designed to circumvent the opposition-led parliament.

President Donald Trump startled observers last week when he said that the US was not ruling out 'a military option' in dealing with Venezuela.

Rubio is thought to have influence on Trump as it relates to US policy toward Caracas.

Washington has denounced Maduro and expressed a clear preference for the opposition.

Like his predecessor, the late Hugo Chavez, Maduro has long warned of an American plot to invade Venezuela and steal the country's oil.

Cabello was a confidant of Chavez, with both men having participated in a failed coup attempt in 1992.

Rubio is a vociferous critic of Venezuelan President Nicolas Maduro (above), the socialist leader of the South American country who has tightened his grip on power despite being deeply unpopular due to a failing economy, food and medicinal shortages

He is currently a powerful political operative who exerts considerable influence over the ruling United Socialist Party of Venezuela.

'We're not surprised by threats from the empire, from its chief Trump,' Cabello wrote Saturday on Twitter.

'In the face of such deranged imperial threats, each person should man their trench. Mine will be next to the people defending the fatherland!'

Washington imposed sanctions on eight Venezuelan officials on Wednesday for their role in creating an all-powerful legislative body loyal to Maduro, but stopped short of action against the OPEC nation's vital oil industry.

More than 125 people have died in violence since the opposition began a sustained wave of protests in April.

Earlier this month, Venezuela inaugurated a new legislative superbody that is expected to rewrite the constitution and give vast powers to Maduro's ruling Socialist Party, defying protests and worldwide condemnation that it undermines democratic freedom.

The UN human rights office said on Tuesday that Venezuelan security forces have systematically wielded excessive force to suppress protests, killings dozens, and have arbitrarily detained 5,000 people since April, including 1,000 still in custody.