Mr. Guaidó was to meet with the Colombian president, Iván Duque, who welcomed him with his own tweet on Sunday, and with Mike Pompeo, the United States secretary of state, who is visiting Bogotá ahead of a trip to the World Economic Forum in Davos, Switzerland. Mr. Guaidó is also bound for Davos.

After years in which President Maduro used repression and electoral machinations to stay in power, despite a crippling recession that left many without enough to eat or adequate medical care, Mr. Guaidó, the head of the country’s National Assembly, challenged his leadership. About a year ago, pronouncing the most recent presidential election a fraud, he declared himself interim president and called for new elections.

President Trump endorsed the opposition leader just minutes after that declaration, and he has remained one of Mr. Guaidó’s strongest international supporters. He followed up his initial recognition with a series of punishing economic sanctions aimed at Mr. Maduro and his government in an attempt to force him to cede power.

But as Mr. Guaidó’s campaign to take power waned over the past year, Washington eased the pressure on Mr. Maduro and turned its attention to the Middle East. That allowed Mr. Maduro to adapt to sanctions, stabilize exports and consolidate political power.

In a sign of the government’s growing confidence, this month Mr. Maduro moved to take over the opposition’s last stronghold, the National Assembly. The government tried to block opposition lawmakers, including Mr. Guaidó, from entering the building, and it installed in their place a rival congressional leadership made up of defectors from the opposition. Most Western and Latin American countries considered the move illegal.