By Nicole Gaouette and Betsy Klein, CNN

(CNN) -- Vice President Mike Pence said the US will impose additional sanctions on Venezuelan leaders and pledged more aid to the region as he called on nations to do more to confront embattled President Nicolas Maduro's government.

"To leaders around the world: It's time," Pence said in Bogota, Colombia, on Monday. "There can be no bystanders in Venezuela's struggle for freedom."

"Nicolas Maduro is a usurper with no legitimate claim to power, and Nicolas Maduro must go," Pence said.

Pence laid out a series of measures the global community should take to support self-proclaimed leader Juan Guaido, including freezing the assets of state-owned oil and natural gas company Petroleos de Venezuela. The company is a central funding mechanism for the government of Venezuela, which sits on the world's largest oil reserves.

More immediately, Pence said the US will sanction three border-state governors and a member of Maduros' inner circle who are implicated in Venezuelan security forces' violent response to the opposition attempt Saturday to bring US-backed aid convoys into the country. The confrontation left more than 300 wounded and at least five dead, Pence said.

Suppressing peaceful protests

"These men worked to block aid for people in need and suppress peaceful protests, their actions will not go unpunished," Pence said, speaking at a gathering of the Lima Group, an international group formed in August to try to find a peaceful resolution to the crisis in Venezuela.

"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 they have stolen and work to return it to the Venezuelan people."

Pence also said the US will offer an additional $56 million in aid to support "our partners in the region as they come to the aid of the Venezuelan people."

The vice president said the US is now identifying new areas along the Venezuelan border with Colombia where aid for Venezuelans can be prepositioned. He called on the countries gathered to crack down on the Maduro regime's money-laundering and other corrupt activities.

Pence urged the international community to cut Venezuela's "worst offenders" off from the global financial system. He also pushed the countries gathered in Colombia to transfer ownership of Venezuela's assets from "Maduro's henchmen to President Guaido's government," restrict visas for Maduro's inner circle and vote to recognize Guaido's representative at the Inter-American Development Bank.

And he called directly on Mexico and Uruguay, both of which have remained neutral, to recognize Guaido.

"We hope for a peaceful transition to democracy, but as President Trump has made clear, all options are on the table," Pence added.

The US military has for the last several days flown an increased number of reconnaissance flights in international airspace off the coast of Venezuela aimed at gathering critical classified intelligence about the Maduro regime, according to two US defense officials.

'All options'

The officials would not detail which US military aircraft are being used, but the Navy and Air Force maintain several large fixed wing aircraft capable of intercepting adversary communications and monitoring the status of adversary weaponry. The officials noted that the effort is limited to whatever the aircraft can gather by staying in international airspace.

Pence directly addressed Venezuela's armed forces, who continue to support Maduro. "For yourselves, your families and your country, we say, make the right choice," Pence said. "Accept President Guaido's sincere offer of amnesty and an inclusive transition to democracy."

Pence noted Guaido's offer of amnesty to members of the military and said the interim president does not seek retribution. But he added that if they continue to support Maduro, they "will ultimately be held accountable ... As President Trump said, 'You will find no safe harbor, no easy exit and no way out. You will lose everything.'"

"We know that what's holding many of you back is not loyalty to Maduro," Pence said, "but fear, fear for your families whom Cuban-trained secret police have kept under constant surveillance."

Secretary of State Mike Pompeo, speaking to Jake Tapper on "State of the Union" Sunday said that, despite Maduro's continued clinging to military power, he believed the situation would shift. "I am confident that the Venezuelan people will ensure that Maduro's days are numbered," he said.

If the Venezuelan military began protecting the people, "I think good things will happen including the restoration of the wealth that was created by those oil fields," Pompeo said.

Asked whether Venezuela's substantial oil reserves played a role in the United States' focus on the conflict, Pompeo said, "We're aimed at a singular mission -- ensuring that the Venezuelan people get the democracy that they so richly deserve and that the Cubans, and the Russians who have been driving this country into the ground for years and years and years, no longer hold sway."

'It's just...aid'

He also pushed back against critics alleging that the White House was using the aid as a negotiating tool to spur regime change.

"This aid went in ... at the request of the legitimate president of Venezuela," Pompeo said, meaning Guaido. "He said, 'Please bring food to my people. Please bring medicine to the sick that are here.' That's what we've been working on these past few weeks."

Tapper asked Pompeo about concerns of groups that cite previous instances of the US smuggling weapons along with aid. "It's just humanitarian aid," Pompeo said.