President Barack Obama with Prime Minister Stephen Harper of Canada and President Felipe Calderon of Mexico (right) after a press conference in the White House Rose Garden on April 2, 2012. The leaders met for the North American Leaders' Summit, at which Calderon pushed for a revival of a ban on assault weapons in the U.S., saying the ban's expiration has led to the spread of guns across the border and a spike in violence in Mexico.

WASHINGTON - Mexican President Felipe Calderon on Monday pushed for a revival of a ban on assault weapons in the U.S., arguing that the ban's expiration has led to the spread of guns across the border and a spike in violence in Mexico.

"The expiring of the assault weapons ban in the year 2004 coincided almost exactly with the beginning of the harshest - the harshest - period of violence we've ever seen," Calderon said, through an interpreter, at a White House news conference on Monday.

The Mexican leader was in Washington to meet with President Barack Obama and Canadian Prime Minister Stephen Harper for summit on economic cooperation and trade between the three countries. But the ongoing drug war in Mexico largely overshadowed those conversations.

In remarks to reporters in the Rose Garden, Calderon urged the U.S. to do more to tamp down on gun trafficking and emphasized that the drug cartels that crime organizations are operating on both sides of the border. He claimed a direct connection between the weakening of gun laws in the U.S. and deaths in his country.

"I know that if we don't stop the traffic of weapons into Mexico, if we don't have mechanisms to forbid the sale of weapons such as we had in the '90s, or for registry of guns, at least for assault weapons, then we are never going to be able to stop the violence in Mexico or stop a future turning of those guns upon the U.S.," he said.

Obama, whose administration has not pushed to reinstate the ban, did not respond to the Mexican president's statement directly. Democrats largely have called a truce when it comes to advancing new gun control legislation, a political calculation based on the party's attempts to appeal to more rural and Western voters.

The president promised to "keep on partnering" with Mexico on security issues.

"We recognize that we have a responsibility to reduce demand for drugs, that we have a responsibility to make sure that not only guns, but also bulk cash isn't flowing into Mexico," Obama said. "Obviously, President Calderon takes very seriously his responsibilities to apply effective law enforcement within Mexico. And I think he's taken courageous steps to do that."

Obama added that "innocent families and women and children being gunned down in the streets, that should be everybody's problem, not just their (Mexico's) problem."

But the administration's primary message aimed at trade. Obama announced a new effort with Canada and Mexico remove outdated trade regulations. The three countries have committed to "sit down together, go through the books and simplify and eliminate more regulations that will make our joint economies stronger," Obama said.

Obama said this is an extension of a White House effort to cut red tape in the U.S. that is aimed at saving businesses and customers more than $100 billion.

When medium and small businesses in the U.S. first start exporting, they usually send their products to Canada and Mexico.

"So this is going to help create jobs, and it's going to keep us on track to meet my goal of doubling U.S. exports," Obama said.

Obama also said that U.S. exports to Canada and Mexico are growing faster than exports to the rest of the world. In 2011, trade with Canada and Mexico surpassed $1 trillion for the first time.