Juan Guaido, a former leader of the Venezuelan opposition, arrived in Miami on Tuesday after making a surprise trip to Colombia the day before, where he announced he would attend an international gathering.

To relaunch stalled negotiations between Venezuela’s government and opposition members in Mexico, Guaido unexpectedly landed in Colombia on the eve of the conference hosted by the leftist government of President Gustavo Petro.

He boarded a plane in Colombia’s capital Bogota on Monday, just hours after he saying on Twitter that he had crossed into Colombia on foot.

“After 70 hours or more of travel I’m still very worried about my family and team,” Guaido told journalists after arriving in Miami, referring to threats they had received.

His visit to Colombia wasn’t warmly welcomed by some officials, and the country’s Foreign Minister Alvaro Leyva said Guaido had entered the Andean country inappropriately.

“Migration Colombia took Juan Guaido, a Venezuelan national who arrived irregularly in Bogota, to El Dorado airport with the aim of ensuring his departure to the United States on a commercial airline,” Colombia’s foreign ministry said late on Monday, adding Guaido had bought his own ticket.

Guaido had hoped to see members of international delegations organized by the government of Colombia’s leftist President Gustavo Petro.

He urged countries participating in the Bogota summit on Tuesday to speak for Venezuelans in exile, being effectively “the voice Maduro wanted to take from me,” he said.

The aim of the conference, to be attended by representatives of 19 countries and the European Union, is to help restart stalled talks in Mexico between the government of Venezuela’s President Nicolas Maduro and opposition politicians.

Guaido, a 39-year-old industrial engineer, headed an interim government beginning in January 2019, before being replaced as head of the opposition legislature at the end of 2022.

Guaido’s political party, Popular Will, rejected his treatment by Colombia’s government, it said in a statement.