Venezuelan President Nicolás Maduro speaks during a meeting with ministers at Miraflores Palace in Caracas on Nov. 2, 2018. (Reuters)

The Trump administration is preparing to add Venezuela to the U.S. list of state sponsors of terrorism in what would be a dramatic escalation against the socialist government of Nicolás Maduro, according to U.S. officials and internal government emails.

The list is reserved for governments accused of repeatedly providing “support for acts of international terrorism” and includes only Iran, North Korea, Sudan and Syria.

Republican lawmakers led by Sen. Marco Rubio (Fla.) have pushed for the designation, citing Venezuela’s alleged ties to Lebanese Hezbollah, the Revolutionary Armed Forces of Colombia, or FARC, and other groups.

Republicans have long accused Venezuela of having ties to terrorist organizations. But experts have played down the threat and strength of those connections. They warn that a designation that does not offer concrete evidence could weaken the legitimacy of the U.S. list, which critics say already is applied inconsistently.

“I suspect this will be based on hearsay and sources of questionable integrity,” said David Smilde, a senior fellow at the Washington Office on Latin America.

U.S. officials declined to say whether a final decision had been made about the designation, but in recent days the State Department has asked for feedback on the proposed move from various agencies, including the Department of Health and Human Services, the Centers for Disease Control and Prevention, which is part of HHS, and the U.S. Agency for International Development.

A State Department spokeswoman declined to comment on the pending decision, calling inquiries about the deliberations a “hypothetical question.”

Rubio, a Cuban American who organized a letter in late September calling for the terrorism designation, has clamored for a tough U.S. posture toward Venezuela, a longtime backer of the Castro regime in Cuba.

The Trump administration has imposed sanctions on a number of people in Maduro’s inner circle, accusing the first lady, defense minister, vice president and other allies of helping the socialist leader “plunder” the nation’s wealth.

Officials have long said that further measures are under consideration, including an embargo on Venezuelan oil. Despite sharply falling oil exports in recent years, Venezuela is the fourth-largest foreign supplier to the United States, which remains the largest purchaser of Venezuelan crude.

Adam Isacson, a Latin America expert, said the terrorism designation might add momentum for any push for an oil boycott. Republicans in Texas and Louisiana, home to refineries set up for Venezuela’s high-sulfur oil, have argued against such a boycott. “A terrorist sponsor designation will make their lives more complicated,” Isacson said.

The move could limit U.S. assistance to Venezuela and prohibit financial transactions as the country reels from hyperinflation and extreme food and medicine shortages that have sent millions fleeing to neighboring countries. Many Venezuelans blame Maduro for rampant corruption across the government and mishandling of the economy.

The country’s health-care system has virtually broken down, allowing once-eradicated illnesses such as measles and diphtheria to reemerge.

Deliberations on the potential U.S. move continued last week, when HHS officials were asked to assess the impact of a terrorism designation on “HHS or CDC programming of funding being carried out by a third party in that country,” according to emails sent among HHS officials.

Officials were asked to provide a response within 24 hours, something a senior HHS lawyer said was “probably not doable” because of the issue’s complexity, according to an official who saw the emails. The person spoke on the condition of anonymity because they were not authorized to discuss the matter.

The emails did not specify the country, but a State Department desk officer identified the country as Venezuela in a telephone call last week with about 20 others from agencies that included HHS, CDC and USAID. The State Department officer, Elizabeth Williams, did not say when a decision on the terrorism designation would be made, “she just said they expect to make a decision soon,” recalled an official who participated in the call. Williams said she was able to share only limited information on the nonsecure telephone line.

Experts are divided on the wisdom of designating Venezuela a state sponsor of terrorism, with some saying it could provide helpful pressure against the increasingly authoritarian Maduro regime, and others expressing concerns that it could play into Maduro’s anti-U. S. messaging or be used as a pretext for a U.S. military intervention.

President Trump, publicly and privately, has raised the possibility of U.S. military action in Venezuela, although aides have repeatedly dissuaded him.

U.S. officials secretly met several times with Venezuelan military officers who said they were plotting a coup against Maduro, but the Trump administration ultimately rebuffed their requests for assistance, officials said.

Smilde fears that the designation could “portray Venezuela as a threat to U.S. national security to legitimize a military option.”

“Many analysts in and around the U.S. government either think military intervention would be effective, or that a credible threat of force would get the Venezuelan government to buckle,” he said.

But such threats “contribute to the unity and coherence of the Maduro government and undermine opposition organization and unity,” he said. “Since President Trump first suggested a military option in August 2017 the Venezuelan opposition has fallen apart.”

Others expressed measured support for a harder line against Maduro, who came to power in 2013, jailed political opponents and took over virtually all legislative and judicial power in the country.

“There are several other governments you could say are involved in more forms of terrorism that have much more impact,” said William Brownfield, the former U.S. ambassador to Venezuela and a senior fellow at the Center for Strategic and International Studies. “But that is a justification for going after other governments, not a justification for saying don’t go after Venezuela.”

“The case can be made that it’s a positive step in terms of bringing greater pressure to bear on the Maduro regime,” he said.

Public health experts have warned of sharp increases in malaria and tuberculosis cases and a nearly absolute unavailability of antiretroviral treatment for people with HIV in Venezuela. Increasing levels of malnutrition compound the health crisis, making Venezuelans both more susceptible to infectious diseases and more prone to complications when sick.

A topic of the phone call between U.S. officials was Venezuela’s growing outbreak of measles, an extremely contagious respiratory infection caused by a virus, which has spread to Brazil, Argentina, Colombia, Ecuador and Peru.

Brazil, which is grappling with more than 10,000 suspected infections in its massive Amazonas state alone, is considering sealing its border with Venezuela, according to the discussion.

Programs that could be affected by the terrorism designation include U.S. support for global HIV/AIDS prevention, emergency vaccines and training of public health personnel, according to the discussion. Most U.S. support is funded through the Pan American Health Organization, a U.N. body.

Brownfield said the president could offset some of the negative humanitarian effects of the designation through waivers.

“I believe the law provides the president with authorities to exempt or waive provisions of the law to allow humanitarian assistance like food or medicine,” he said.

The possible action against Venezuela came as a surprise to people on the call, the official said. “That was the first we had heard of it,” the official said. “It didn’t make sense. And then it was like, ‘Oh, crap. What is this going to do to our ability to respond to the slow-moving health disaster that is coming out of Venezuela?’ ”

Karen DeYoung and Greg Jaffe contributed to this report.