Venezuelan opposition leader Juan Guaido surfaced in Colombia on Sunday to meet with US Secretary of State Mike Pompeo, as his power struggle with President Nicolas Maduro entered a challenging new phase.

“Already in #Colombia,” the Venezuelan National Assembly leader wrote on Twitter, thanking Colombian President Ivan Duque for his “support for the struggle”.

The move comes after an overture by Maduro for direct negotiations with the US on an end to its crippling sanctions, and amid signs he is preparing for renewed confrontation with the opposition.

Guaido, who is recognised by the US and more than 50 other countries as Venezuela’s acting president, will meet with Pompeo in Bogota.

Pompeo told reporters on a flight from Germany to Colombia that Guaido was “the duly elected leader of Venezuela”.

“I look forward to having a meeting with him,” Pompeo said. “Maduro has been destructive … Our mission set is to deliver a set of free and fair elections to the Venezuelan people.”

The US secretary of state is scheduled to arrive in the Colombian capital on Monday at the start of a Latin American tour.

“We will generate the conditions that will lead us to liberty,” Guaido said, anticipating he would return to Venezuela “full of good news”.

Duque, also on Twitter, said he would hold a working meeting with Guaido, and that they would both attend a regional summit on Monday on the fight against terrorism.

Guaido was barred from leaving Venezuela since proclaiming himself acting president a year ago after the National Assembly declared Maduro a “usurper”.

He has defied the travel ban once before, in February, when he secretly travelled to Colombia and then visited several other countries to marshal regional support for his challenge to Maduro.