Reporting from Washington and Mexico City -- President-elect Barack Obama met with Mexican President Felipe Calderon in Washington on Monday to begin work on one of the most vital yet challenging of U.S. relationships.

As a symbol of the ties between the two nations, incoming U.S. presidents traditionally meet with Mexico's leader before meeting with other heads of state or government. The meeting between Obama and Calderon, who heads Mexico's conservative National Action Party, was their first opportunity to address the global economic slowdown, drug violence along the border, immigration and trade.

During the U.S. presidential campaign, Obama expressed skepticism about the North American Free Trade Agreement between the U.S., Canada and Mexico, saying at one point that he favors reopening negotiations. The meeting at the Mexican Cultural Institute gave Obama the chance to address the relationship.

"I believe it can be even stronger, and that's going to be the commitment of my administration," he said after the meeting.

For his part, Calderon said cooperation was necessary in the fight against drug cartels and as regards mutual security. "It will be the beginning of an extraordinary age in the relationship between the United States and Mexico," he said.

Obama might have had an easier job winning Calderon's confidence if New Mexico Gov. Bill Richardson had not withdrawn recently as Obama's nominee to be Commerce secretary following reports that his office was the subject of a federal corruption investigation.

Richardson, who grew up in Mexico and whose 95-year-old mother still lives there, was regarded by Mexicans as an important advocate. A free-trade Democrat, Richardson was seen as a key voice at the White House table for NAFTA.

The visit gave Calderon a chance to outline his nation's needs to an incoming U.S. president who has not been south of the Rio Grande. Still, most Mexicans saw the stop more as a courtesy call than a key moment in the sometimes prickly relationship between the two nations.

In two years as Mexican president, Calderon has had a soul mate in President Bush, a fellow conservative with a pro-business bent who has staunchly backed Calderon's offensive against drug traffickers. Bush pushed for passage of a $1.4-billion package of security aid, known as the Merida Initiative, to give Mexico aircraft, high-tech scanning gear, safety equipment and training. The first $400 million, approved by Congress last year, has begun flowing.