Vice President Pence and Venezuelan opposition leader Juan Guaidó greet each other at the Lima Group meeting in Bogota, Colombia. (Luisa Gonzalez/Reuters)

After a weekend of high drama but few results at Venezuela’s border, the United States and other nations appeared resigned Monday to the fact that forcing President Nicolás Maduro from power will be neither quick nor easy.

Vice President Pence, addressing a group of Latin American leaders in Bogota, Colombia, repeated the Trump administration’s assurance that “all options” are on the table but offered up only minor new U.S. sanctions.

In his address to the Lima Group, the 14-nation diplomatic consortium supporting Maduro’s replacement with opposition leader Juan Guaidó, Pence gave no indication that the United States was ready to use force.

Despite previously indicating that he would announce “clear actions” in response to violent clashes at the border this weekend, Pence reiterated an amnesty offer for the Venezuelan military, emphasized continued “economic and diplomatic” measures against Maduro, and urged other nations to exert more pressure.

The group agreed on a declaration calling for a transition to democracy “peacefully, by the Venezuelans themselves . . . supported by political and diplomatic means, without the use of force.”

The only participants at the gathering who seemed to favor a more muscular approach were Guaidó and the opposition he leads. On Sunday, he tweeted that he would pose a formal question to international backers, asking that “all options [be] open to achieve the liberation of this country.”

Senior opposition politician Julio Borges was more direct, tweeting that the opposition “will urge for an escalation of diplomatic pressure and the use of force against the dictatorship of Nicolás Maduro.”

Pence acknowledged to reporters Monday that Guaidó sought assurances that the United States could use force if necessary. “I reassured him” that force remains an option, Pence said, “but we hope for better. We hope for a peaceful transition.”

The military option has not disappeared, said one senior Latin American official who attended the meeting. “It’s the elephant in the room. But nobody wants to see it, and nobody wants to talk about it. . . . There has been no discussion whatsoever regarding it.”

Progress has been made, the official said. “When you look at what has happened in the last month,” with dozens of nations recognizing Guaidó as Venezuela’s legitimate president and piling sanctions on Maduro, “we never thought we would be here.”

“But this is just starting. The economic pressure, the diplomatic pressure is just starting,” said the official, who spoke on the condition of anonymity about the sensitive diplomatic talks. “Saturday and Sunday weren’t as successful as we had hoped, but that’s just part of the learning process.”

Amid the post-weekend letdown, it seemed clear that the opposition had become a victim of its own hype, claiming that a humanitarian “D-Day” — with aid-laden trucks and thousands of cheering supporters coming face to face with Venezuelan security forces across the Colombian border — would burst the dams of Venezuelan military frustration and bring about a massive rupture between the armed forces and Maduro.

Instead, about 160 rank-and-file troops abandoned their posts; symbolically significant, but nowhere near the flood of support the opposition needed. At the same time, only minimal amounts of aid got through. As many as eight people were killed, according to the opposition, and hundreds were injured.

“They started talking about the inevitability of winning, that humanitarian aid can’t be stopped,” said David Smilde, a fellow with the Washington Office on Latin America. “Yes, those are great to mobilize people. But the problem is being caught flat-footed. They’ve got to figure out a new plan to manage expectations.”

For Guaidó in particular, the weekend set up a high-stakes choice. His decision to go to Colombia allowed him to bask in the international spotlight and solicit more support. But he had left Venezuela in violation of a travel ban issued by Maduro’s Supreme Court and is now publicly on the record suggesting a foreign military intervention.

Senior opposition figures said Guaidó plans to return to Venezuela. But Carlos Holmes Trujillo, Colombia’s foreign minister, warned Monday that he faces serious risks in doing so.

“We have information of serious and credible threats to the life and personal integrity of Juan Guaidó and his family, and his wife’s family,” Holmes said. “From Bogota, we want to make the usurper Maduro responsible for any violent action against Guaidó and his family members. It would be not only another crime but would also lead to an international situation that would force the whole Lima Group to use all the legal and political mechanisms available to it.”

If he does not return to Venezuela, Guaidó risks taking the wind out of the sails of a re-energized opposition — a once moribund and divided movement that he almost single-handedly brought back to life.

“They thought it was going to be over, if not close to over,” Michael Shifter, president of the Washington-based Inter-American Dialogue, a think tank, said of the opposition. “They thought they’d get some aid in, that more of the senior military officials would flip.”

“It just didn’t happen,” Shifter said. “So, they say, ‘What do we do next?’ The problem is if they continue to have the same strategy,” using diplomatic and economic pressure, “it drags on. And if it drags on, there may be some real splits within the opposition.”

Pedro Burelli, a Washington-based opposition activist and former founding director of PDVSA, Venezuela’s national oil company, agreed. “I think this was to be expected,” he said of the weekend’s events. “Anybody who thought this would work was fooling themselves.”

Sanctions are an equally high-stakes endeavor that risks worsening the already dire humanitarian condition of Venezuelans.

The United States has used the “nuclear option” against Venezuela, confiscating revenue from oil exports into this country that have provided the bulk of its operating cash in recent years. Under the sanctions imposed last month, Venezuela can continue sending oil to the United States, but any revenue it generates is to be held in blocked U.S. accounts.

Mismanagement and corruption have seen Venezuela’s oil exports drop to 1.1 million barrels a day last month, less than a third of its production when Maduro mentor Hugo Chávez took over the country two decades ago.

Although China and Russia are still receiving Venezuelan oil, those sales generate no income, said Russ Dallen of investment bank Caracas Capital Markets, because they were prepaid with loans that Maduro long ago spent.

Current shipments to China, Dallen said, total 300,000 to 400,000 barrels a day, with 200,000 to 300,000 more going to Russia as its portion of a joint venture. An additional 400,000 barrels a day theoretically goes to India — where Russia owns one of two refineries that handle heavy Venezuelan crude — although Venezuela lacks the ultra-large tanker ships to make up for the long-distance transport costs.

Chevron, which also operates a joint venture with PDVSA, still imports Venezuelan crude under a provision in the sanctions that gave it a six-month grace period.

Gearan reported from Bogota, and Faiola reported from Caracas, Venezuela. Carol Morello and John Wagner in Washington contributed to this report.