Colombia's national oil company said Monday that it will begin ramping up shale oil production in the country, as Vice President Mike Pence visited the country to discuss trade and the crisis in Venezuela.

"After the United States and Vaca Muerta [shale region] in Argentina, our non-conventional play seems to be the most substantial in terms of oil in the Western Hemisphere," Ecopetrol CEO Juan Carlos Echeverry told Reuters. He said experts calculated that recoverable oil could be between 2.5 and 7 billion barrels.

"Non-conventional oil" is a term for oil taken from shale rock formations using the hydraulic fracturing drilling method, or fracking. Fracking and shale oil and natural gas have made the U.S. one of the top producers of fossil fuels in the world in less than a decade.

The national oil company's announcement came as Pence met with Colombia President Juan Manuel Santos over the weekend amid the ongoing crisis in Colombia's neighbor, Venezuela. Santos and Pence discussed the situation there, with Pence reiterating President Trump's "commitment to bring the full weight of U.S. diplomatic and economic weight to bear to restore its democracy," according to the White House. They also discussed trade and continuing commercial ties between the two countries.

Echeverry said he will require expertise from elsewhere to assist in Ecopetrol's shale production. "We are not unconventional experts and so we would seek partners with know-how," he said. Houston-based Occidental Petroleum, which has operations in Latin America and the Middle East, and Shell oil, are interested, according to Reuters.

He said shale production will drive the company's strategic focus over the next decade to boost its reserves.

U.S. consultants at Wood Mackenzie said the Colombian government wants to promote shale oil and gas production to "ward off expected future shortfalls in domestic production," according to an analysis released late last year.

The largest shale oil reserves are believed to be within the country's Middle Magdalena Valley basin. Ecopetrol supplies the country with more than 60 percent of its oil needs, which makes it less dependent on imports from Venezuela, which is a major global producer and member of OPEC.

Colombia is South America's third-largest oil producer after Venezuela and Brazil, according to the Energy Information Administration. It is the fifth-largest exporter of oil to the United States, and a major coal exporter, ranking as the fifth largest in the world in 2015.