Cartagena, Colombia (CNN) -- Regional summits are most often perfunctory events where presidents share their visions, sign agreements and pose for photographs.
At the sixth Summit of the Americas, some Latin American leaders hope to sway -- or at least challenge -- the priorities of the hemisphere's largest power, the United States.
The leaders of some Latin American countries are expected to challenge the conventional wisdom that the way to deal with illegal drug trafficking is with firepower. Guatemalan President Otto Perez Molina and others are offering serious alternatives, such as legalization.
"My position is -- let's discuss it," said Colombian President Juan Manuel Santos, who is hosting the event. "We must ask each other, are we doing the best we can? Sometimes the answer is no. The consumption is going up in many countries."
Santos said that Latin America wants to pull Washington's attention toward the region.
The United States needs to realize that its long-term interests are not in places like Afghanistan, but in Latin America, Santos said.
"What I hope that can come out of this summit is that the U.S., but not only the U.S. government, the U.S. businessman, the U.S. public opinion, starts to look at Latin America with different eyes, as an opportunity, not as an area full of problems."
Presidents from the Western Hemisphere arrived Friday in the coastal Colombian city of Cartagena, ahead of several days of discussions on such topics.
Venezuelan President Hugo Chavez's attendance remained uncertain Friday night, when he told Venezuelan National Television, "In reality, that won't be decided by me, but by the doctors."
Chavez said he would return Saturday to Havana for more cancer treatment.
But he said a Venezuelan presence was required in Colombia to answer "American imperialism" and protest Cuba's exclusion from the summit, adding that Venezuelan Foreign Minister Nicolas Maduro might represent Venezuela in his place.
Santos recommended the United States seek closer relations with Havana. "I think that, by embracing Cuba, one would be in a better position to press for reforms and more democracy and more freedom in Cuba," the Colombian president said.
Asked whether he was going to press Obama on that issue, he said, "It's a very sensitive issue in states like Florida. I understand his reluctance to discuss this at this moment."
While the balance of power between the United States and the rest of the hemisphere will be a certain talking point, Santos also laid out an agenda for Latin American countries to tackle among themselves.
They include fighting poverty, improving access to energy, building infrastructure, preparing to better respond to natural disasters and increasing access to technology. "What I would prefer more besides this is a new way of talking to each other, more as partners, more as equals, and more conscious of the need that we have of each other," he told a reporter.
There is no dogma or specific type of government that can ensure development, Santos said. It takes a moderate approach in the mold of leaders such as former British Prime Minister Tony Blair or former American President Bill Clinton who governed from the middle, he said.
Some recent Latin American leaders, such as Ricardo Lagos of Chile and Luiz Inacio Lula da Silva of Brazil, advanced their nations by also following the centrist, so-called Third Way.
"If we play our cards right, with a long-term vision, and thinking big, being ambitious, we can finally say ... that the future is here," Santos said.
U.S. President Barack Obama arrived Friday.
On a quick visit to Tampa ahead of his flight to Cartagena, Obama spoke with small-business owners about his own agenda.
"In Latin America alone in the last decade, tens of millions of people have stepped into the middle class," he said. "That means they have more money to spend, we want them to spend more money on American-made goods."
"While I am in Colombia talking to other leaders, I am going to think about you," Obama added. "I want to sell our stuff and put Americans back to work."
The goal of the summit is to "unite against the ills of the 21st century. Like poverty, terrorism and global warming," Chilean President Sebastian Pinera said. "And also, to unite to achieve the great goal that America has to conquer -- and it is the responsibility of our generation -- to make America a developed continent without poverty, with opportunity for all."
More than 7,600 police officers and thousands more troops were expected in the walled colonial city as part of stepped-up security for the summit, which started Monday with a youth conference.
The summit has brought a different vibe to the tourist destination. The number of tourists has dropped tremendously this week, locals said.
Tourism has fallen by "90%," street vendor Alcides Escobar said. "Who we have here is just people from the summit and their security."
CNN's Patrick Oppmann and John Helton contributed to this report.