MEXICO CITY - Gov. Janet Napolitano flew home to Arizona on Saturday, having spent much of her 48-hour stay here talking cross-border trade with high-ranking Mexican officials, including President Felipe Calderon.

However, after news broke Thursday that three illegal immigrants had been shot and killed near Tucson, most of the governor's time with the media was spent answering questions about U.S. border policy.

Still, while the public face of her visit was colored largely by the issue of immigration, Napolitano said her closed-door talks had established "a framework for progress in a lot of areas" that would result in improved relations between Arizona and Mexico.

After her arrival Thursday afternoon, the governor met with Mexico's agricultural and transportation secretaries to review efforts that would move more Mexican cattle and agricultural products through Arizona's land ports of entry.

She then began her day Friday by discussing border security and the need for immigration reform with Public Security Secretary Genaro Garcia and Foreign Relations Secretary Patricia Espinosa. Napolitano also talked tourism with executives at the airline Aeromexico, which recently began non-stop service between Mexico City and Phoenix.

When she met with Calderon on Friday, Napolitano and the governor of Sonora, Eduardo Bours, stressed the need for road and railway development in Sonora to facilitate more cross-border commerce.

Meanwhile, a group of Arizona business leaders traveling with the governor met with several Mexican counterparts, including Carlos Slim, currently ranked by Forbes magazine as the world's third-richest man. And representatives from Arizona's three public universities spoke with Mexican education officials to share ideas on academic cooperation.

Asked by a U.S. reporter if Arizonans understand the complexity of the state's relationship with Mexico, Napolitano offered a mixed reply.

"I think Arizonans know quite a bit - particularly those who live in southern part of state whose jobs and livelihoods are attached to trade to and from Mexico," she said. "And we're talking tens of thousands of jobs in our state."

However, she added, because the problem of illegal immigration has become so big that it has also become the sole issue that some Arizonans think of when they think of U.S.-Mexico relations.

It was also apparent during the trip that immigration defines the way many Mexicans view Arizona.

When Napolitano's commercial flight landed Thursday at Benito Juarez International Airport, it was met by a gaggle of domestic reporters and TV cameras. The media crush, however, was for another passenger on the same plane - porn star Brooke Haven, who had come to Mexico City on a promotional trip.

The governor's press conference later that day was sparsely attended, and only by members of the international press corps.

But after the deadly shooting in Arizona made Friday's front pages, a media event that evening was packed with domestic reporters and photographers. And many of their questions were rhetorical in nature, suggesting those who kill illegal immigrants in Arizona act with impunity, and that the failure to achieve comprehensive immigration reform in the U.S. was a result of racism toward Mexican migrants.

A press release from Calderon' office also stressed immigration over trade, tourism or cultural exchanges. The statement said the president had expressed his concern to Napolitano over what he described as "increasingly bold" attacks against immigrants in Arizona.

Such incidents, he said, create a climate that is not conducive to cooperation on other fronts.

For her part, Napolitano said episodes such as Thursday's killing and last month's deadly Border Patrol shooting near Naco underscore the urgent need for comprehensive immigration reform in the U.S.

"We need the Congress of the United States to take up immigration," she said.

But the governor also stressed the need for more manpower at the border and said she was pleased with the work of the National Guard troops who were deployed to the U.S.-Mexico border beginning last year.

Napolitano said the Guard's mission at the border had been misinterpreted in Mexico, where the deployments were widely criticized.

Emphasizing her desire to promote good relations between Arizona and Mexico, Napolitano recalled a quote from former Gov. Paul J. Fannin, who said of the two countries: "God made us neighbors, let us be good neighbors."

The trip was Napolitano's third official visit to Mexico City and her first since Calderon took office on Dec. 1. She said she had invited Calderon to come to Arizona, though no date had been set.