The US has long hoped that a post-Chavez era could herald a new era in ties with Venezuela, but allegations of a US plot to kill the leftist leader show any rapprochement is still far off, AFP reports.
After a long battle with cancer, President Hugo Chavez died on Tuesday, aged 58, throwing his country's immediate political future into doubt and leaving Washington wondering what lies ahead for the Latin American nation.
"I think the hardest days for our relationship with Venezuela are not behind us, they are ahead of us," warned Carl Meacham, director of the Americas program with the Center for Strategic and International Studies.
"The willingness is there" from America, he told AFP, "I just don't think it's in the Chavista group's interests to make nice with the United States."
Within hours of Chavez's death, US President Barack Obama said Washington hoping for "constructive" future ties with the major oil-producing nation.
But he added: "As Venezuela begins a new chapter in its history, the United States remains committed to policies that promote democratic principles, the rule of law, and respect for human rights."
Caracas and Washington have been operating embassies in each country without an ambassador since a diplomatic spat in 2010.
And analysts said it would be business as usual, particularly after Chavez's anointed heir, Vice President Nicolas Maduro blamed Washington of a conspiracy to kill his mentor and expelled two US Air Force attaches.
"I think it was a sign the Chavez brand of accusing the United States of every possible crime will continue," Ted Piccone, deputy director of foreign policy for the Brookings Institution, told AFP.
"The US approach for these many years has been to lay fairly low, don't make the United States the story, don't give Chavez even more ammunition."
US officials have denounced Maduro's allegation as absurd, but Piccone said it highlighted the "very strong ideological affinity for an anti-US agenda" in Venezuela.
CSIS expert Meacham agreed, saying Maduro now had to shore up his base within the Chavismo movement, with some intense political jockeying likely in the coming days ahead of elections.
"The question you have to ask yourself is, how does a Chavista benefit from making friends with its arch enemy? We believe in capitalism, we believe in free markets, we believe in things that are completely contrary to the Chavista system," he said.
Maduro took over as interim president and elections will be called within 30 days, Foreign Minister Elias Jaua told state news channel Telesur.
"It is the mandate that comandante President Hugo Chavez gave us," Jaua said, but worryingly adding there was an "absolute absence" over the constitutional procedure to replace Chavez.
Former assistant secretary for Western Hemisphere Affairs, Roger Noriega, told AFP"the international community should press Venezuelan authorities to respect the constitution."
"I think there's a division within Chavismo right now, everyone has to be very prepared for unrest, instability," he warned.
"Hugo Chavez's death is a game changer in Venezuela and will inevitably imply a reorganization of the political order," agreed IHS Latin America analyst Diego Moya-Ocampos in a written note.
He warned though of a power vacuum and fears of political instability. While others cautioned violence could erupt, stressing the military role will be key.
"Imagine the folks that are very impassioned supporters grieving for Mr Chavez and imagine the students that are demanding elections and feel betrayed, feel they were lied to about Chavez's health... You put all that together and you have a pretty potent, toxic mix," said Meacham.
Assistant Secretary for Latin America Roberta Jacobson in a statement offered sympathies to Chavez's family and friends, adding "we stand ready to support Venezuela during this period."
In late November, when it was already known that Chavez was ill, she had reached out to Maduro to talk by telephone, and US officials say Washington has proposed some ideas on how to improve ties step-by-step.
With Chavez's funeral now set for Friday, a key indicator of US-Venezuelan ties will be who, in the absence of an ambassador, Washington sends to a ceremony likely to be packed with other left-leaning anti-US leaders.
"Would the US respond by actually sending someone higher level than Roberta Jacobson? I think they would be smart to do it. I think they will be looking around to see who else goes," Piccone said.