The has United States targeted Venezuela's government with new sanctions and called on allies to freeze the assets of its state-owned oil company PDVSA after deadly violence blocked aid from reaching the crisis-hit country during the weekend.
The US also took its pressure campaign to the United Nations Security Council, asking that body to discuss the situation in Venezuela, diplomats said.
The US Treasury Department's sanctions were imposed on four Venezuelan state governors allied with the government of embattled President Nicolas Maduro, blocking any assets they control in the United States.
The new sanctions were announced in Bogota as US Vice President Mike Pence and opposition leader Juan Guaido met with members of the Lima Group, a bloc of nations from Argentina to Canada dedicated to peaceful resolution of the Venezuelan crisis.
Pence said the United States would stand by Guaido until freedom was restored to the OPEC member. He called for all Lima Group nations to immediately freeze PDVSA's assets and to transfer ownership of Venezuelan assets in their countries from Maduro's "henchmen" to Guaido's government-in-waiting.
He also said tougher measures were coming.
"In the days ahead ... the United States will announce even stronger sanctions on the regime's corrupt financial networks," Pence said. "We will work with all of you to find every last dollar that they stole and work to return it to Venezuela."
Guaido, sitting next to Pence at the meeting, asked for a moment of silence for those killed in what he called the "massacre" of the weekend.
At least three people were killed and almost 300 wounded during the protests and clashes on Saturday as US-backed aid convoys attempted to enter Venezuela to deliver food and medicine.
Guaido, recognized by most Western nations as Venezuela's legitimate leader, has urged the bloc to consider "all options" in ousting Maduro.
Pence repeated an earlier statement that there would be an amnesty for members of the armed forces who throw their support behind Guaido. He said he hopes Maduro and those supported by his "corruption and his brutality" will leave Venezuela peacefully.
"We make clear to them that we will support the interim president's call for amnesty, an inclusive government, an inclusive future for members of the armed forces, who have laid down their arms and stand with the Guaido government," Pence said.
Unlike the Lima Group, of which the United States is not a member, the Trump administration has so far declined to rule out the use of military force. But Peruvian Deputy Foreign Minister Hugo de Zela Martinez denied there was any division in the group over the use of force.
Pence also called for Mexico and Uruguay, two-left leaning regional governments, to join most of the region's other powers in embracing Guaido as Venezuela's rightful president.
"We believe there can be no bystanders, no one on the sidelines of this, particularly in our hemisphere, and our message today very much was intended to say - to Mexico, to Uruguay, to nations across the eastern Caribbean - that they need to come off the sidelines, they need to take a stand for freedom. Stand with us and with the people of Venezuela," said Pence.
Washington wants the 15-member UN Security Council to formally call for free, fair and credible presidential elections with international observers. Russia, which along with China has major investments in Venezuela's energy sector and back Maduro, proposed a rival draft resolution.
Violence escalated during the weekend when the convoy of trucks with food and medicines was blocked by soldiers and armed groups loyal to Maduro. He said the aid efforts are part of a US-orchestrated coup against Venezuela.
In the Venezuelan town of San Antonio, near the border with Colombia, residents on Monday chafed at the continued border closure ordered by Maduro's government last week.
Residents increasingly cross into the neighboring country to work and buy basic goods that are unavailable in Venezuela, which has been wracked by years of hyperinflation and shortages of food and medicine. Illegal crossings over back roads known as "trochas" generally require paying tolls to low-level criminals who control them, known as "trocheros."
"We were hungry when before the border closed. Now it will be even worse," said Belkis Garcia, 34, walking with her husband along a trail that leads to Colombia. "We have to pay (to cross), so the little money we have for half the food is not enough. We don't know what will happen if the border continues closed."
Four people have been killed, 58 have suffered bullet wounds and at least 32 arrested in unrest since Friday, local rights group Penal Forum said in a press conference.
Meanwhile, Brazilian Vice President Hamilton Mouro said on Monday that under no circumstances would his country allow the United States to intervene militarily in Venezuela from Brazilian territory.
"Nobody is betting on a military solution," Mouro, a retired general, told reporters in Bogota during a meeting of the Lima Group, a bloc of nations from Argentina to Canada dedicated to peaceful resolution of the Venezuelan crisis.
The Lima Group would not back an invasion by the United States, Mour+o said, and will continue stepping up diplomatic, political and economic pressure on what he called the "regime" of Venezuelan leftist President Nicolas Maduro.