"The United States and its allies will not quit this fight," Pompeo said on Friday during an event in Chilean capital Santiago, adding that the country would keep supporting Venezuela’s opposition.
"It's a historic opportunity when you have all but a handful of countries that are truly market-driven, democratic in ways that you haven't had in South America for decades," Pompeo told reporters earlier en route from Washington to Santiago, Presstv Reported.
The top US diplomat is on a three-day trip to Latin America, where he is visiting Chile, Paraguay and Peru, a region where Washington's concerns are focused on China's growing presence as well as the Venezuelan crisis.
Pompeo is also expected to briefly visit a Colombian border city receiving significant numbers of Venezuelan migrants.
Venezuela has been in political turmoil since US-backed opposition figure Juan Guaido declared himself “interim president” in January.
The administration of US President Donald Trump has imposed a raft of sanctions against the government of Venezuelan President Nicolas Maduro in an attempt to remove him from power.
Critics have warned that heavy sanctions could hurt ordinary Venezuelans, already suffering from hyperinflation and food and medicine shortages.
The Trump administration has also threatened to use military force to topple Maduro.
Washington is pressuring Maduro to resign and urging more countries to join the coalition supporting Guaido.
Maduro blames US sanctions for the country's economic problems and dismisses Guaido as an American puppet.
Pompeo also accused China and Russia of aiding Maduro's government and urged the people of South America to resist offers of investment and aid from Beijing and Moscow.
America’s regional influence in South America has been increasingly challenged by China and Russia, both of whom have invested in that region.