Talks between the US and Russia have been positive, an official says, but "who gets the title of president" remains in dispute as Moscow backs Nicolas Maduro.
US President Donald Trump on Tuesday urged Venezuela's military to desert President Nicolas Maduro, in a joint appeal with Brazil.
"We call on members of the Venezuelan military to end their support for Maduro, who is really nothing more than a Cuban puppet," Trump told a joint news conference at the White House with Brazil's new right-wing president, Jair Bolsonaro.
Earlier talks between the United States and Russia on Venezuela were positive and substantive but the two sides are still divided over the legitimacy of President Nicolas Maduro, a US official says.
"No, we did not come to a meeting of minds, but I think the talks were positive in the sense that both sides emerged with a better understanding of the other's views," US special representative Elliott Abrams told reporters on Tuesday.
"They were useful, they were substantive, they were serious. We agreed very much on the depth of the crisis in Venezuela. We are, as they, deeply concerned about the nature and the seriousness of the humanitarian crisis," he said.
The US and many other Western countries back Juan Guaido, head of the opposition-controlled National Assembly who invoked the constitution in January to assume an interim presidency.
Russia says Maduro remains the country's only legitimate leader. "Who gets the title of president" was still a point of contention, Abrams said.
The Russian delegation at the talks, which took place in a Rome hotel and lasted more than two hours, was headed by Deputy Foreign Minister Sergei Ryabkov.
Meanwhile the US imposed sanctions on Tuesday against Venezuela's state-run goldmining company Minerven and its president, Adrian Perdomo, accusing them of illicit operations and propping up Maduro's government.
The announcement comes days after Uganda said it was investigating its biggest gold refinery for importing Venezuelan gold. Washington has imposed half a dozen rounds of sanctions against Maduro and senior Venezuelan officials as it tries to choke off funding to the government.
It has warned gold traders not to deal in Venezuelan gold or oil.
"Treasury is targeting gold processor Minerven and its president for propping up the inner circle of the corrupt Maduro regime," US Treasury Secretary Steven Mnuchin said in a statement.
Maduro is under intense pressure to step down amid a deep economic crisis in Venezuela and as the government faces widespread international condemnation after he was re-elected last year in a vote that has been seen as fraudulent.
"We will aggressively pursue those involved with Maduro's reckless illicit gold trade which is contributing to this financial, humanitarian, and environmental crisis," Mnuchin said.