In the thick of political contests in both the United States and Mexico, Obama and Mexican President Felipe Calderon traded unusually direct claims about the cause and effect of the drug violence that has consumed a swath of northeastern Mexico. They were cordial and complimentary to one another, but did not hide the degree of worry on both sides about a six-year spasm of violence that has killed more than 47,000 people.
"It can have a deteriorating effect overall on the nature of our relationship," Obama said. "And that's something that we have to pay attention to."
Calderon made a government crackdown on warring drug cartels the hallmark of his six-year term, which expires later this year. His center-right party has seen its election chances fall in the face of a wide perception in Mexico that the crackdown has not worked.
RELATED: Gas prices a top issue for US-Canada-Mexico summit
The Mexican presidential election that formally began last week will culminate with elections July 1.
Beyond the terrible human cost, the battling drug gangs in Mexico and in Central America cause economic problems and political and security concerns for the United States, Obama said.
"If they're undermining institutions in these countries, that will impact our capacity to do business in these countries," Obama said following meetings with Calderon and Canadian Prime Minister Stephen Harper.
The three leaders launched a new bid to pare back regulation and boost North American trade.
After a one-day summit, Obama said the United States has trimmed outdated and burdensome rules in talks with both its neighbors, but all three countries will now go beyond that.
"Our three nations are going to sit down together, go through the books and simplify and eliminate more regulations that will make our joint economies stronger," he said.
Obama noted trade among the three neighbors now tops $1 trillion a year, and he wants to see that number rise. "This is going to help create jobs," he said.
The summit ranged broadly across issues of energy and climate change, immigration and the fight against the drug trade.
Obama warned of a possible "spillover effect" on American tourism and American expatriates living in Mexico and bordering nations that also have had problems with drug cartels.
Sounding testy, Calderon remarked that no American "spring-breakers" were harmed in Mexico this year. Mexico is a favorite place for U.S. college students to spend their springtime holiday breaks from school.