"Drugs is a big, big problem in America. The continued flow of drugs from Colombia through Mexico into the United States is still one of our major challenges for all Americans," McCain told ABC's "Good Morning America" Wednesday in an interview from Cartagena.
McCain was also promoting free trade deals like NAFTA he said would benefit the U.S. economy over time, even though such agreements have been deeply unpopular in several general election swing states like Ohio and Michigan.
McCain acknowledged that the economy is a top concern for many voters, and said he is better prepared to deal with the economy than his Democratic rival, Illinois Sen. Barack Obama.
"I'm very strong on the economy," McCain said. "I understand it, I have a lot more experience than my opponent."
In December, McCain told reporters: "The issue of economics is not something I've understood as well as I should."
The Arizona senator was also meeting with cabinet ministers and business leaders. He was scheduled to depart Wednesday afternoon for Mexico City.