The U.S. government also sees European allies as likely to do more to prevent Maduro from transferring or hiding Venezuela government assets held outside the country, the U.S. official said.
Venezuela's dire situation has fuelled a political crisis that has peaked over the last month with Guaido invoking a constitutional provision to declare himself the legitimate, interim president.
While the 35-year-old has the support of powerful western nations, other global powers such as Russia, China and Turkey continue to back the Maduro regime and have denounced what they call foreign meddling in Venezuela's internal affairs.
The Red Cross urged Venezuelans not to politicize the aid issue, without saying how or if the aid would arrive.
Abrams, a long time Republican foreign policy player who helped steer Ronald Reagan's controversial backing of anti-communist forces in Central America - said that countries should only deal with Guaido.
The goods, including packaged corn flour, lentils and pasta, arrived Thursday in what the opposition is hoping will be the first of many shipments of humanitarian aid from countries around the world.
The same day, Reuters reported that the United Nations warned against "politicizing humanitarian aid in Venezuela". He was arrested last month after he entered Venezuela clandestinely from Colombia.
Images show an orange oil tanker and two large blue containers positioned midway across the three-lane Tienditas Bridge, which connects Cucuta with San Antonio city in Tachira State in western Venezuela.
The Times noted that there were other border roadways that were open where vehicles could cross, calling the blockade "a show of defiance by the government of President Nicolas Maduro". But the aid blockade could lead to troops disobeying Maduro's orders and allowing the much-needed aid to pass.
Venezuela supports the dialogue process proposed by Mexico, Uruguay, Bolivia and the Community of Caribbean Countries (CARICOM), Maduro said at a press conference in the Miraflores Palace in Caracas.
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The Trump administration last week issued sweeping sanctions against state oil company PDVSA, froze profits generated by refining subsidiary Citgo, and has vowed to starve Maduro's government of all revenue. Speaking earlier to RT Spanish, Maduro called the aid a form of intervention, and said he would not accept it.
Maduro's government has accused Guaido, who has galvanized Venezuela's opposition, of attempting to stage a USA -directed coup.
He did not provide any details on how the United States military might respond.
On Friday morning an awning was set up on the Venezuelan side of the Simon Bolivar pedestrian bridge, the main point of entry between the two Andean countries, in aim of collecting signatures in support of Maduro to remain president of Venezuela.
CNN could not independently verify the authenticity of the video.
The opposition leader launched a bid to oust Maduro last month, declaring himself interim president, a move recognized by the United States and around 40 other countries, including 20 from the European Union.
"Is John Bolton Venezuela's military chief?"
Pascual says it's "unthinkable" the armed forces would abandon Maduro "because of the high command's vested interests in oil and mining". "Let's say our slogan loudly, "Loyal Always, Traitors Never" so it can be heard in Washington", he said.
Maduro said he was willing to meet with envoys of the so-called International Contact Group, that is backed by the European Union, but said a statement from its first meeting on Thursday was partisan and ideological.
It's unclear what will break the standoff playing out at the Venezuela-Colombia border.