Updated

U.S. Secretary of Homeland Security Janet Napolitano said Thursday that security on the southern U.S. border "is better now than it ever has been" and that violence from neighboring Mexico hasn't spilled over in a serious way.

Napolitano spoke at the Bridge of The Americas border crossing, after a meeting with the mayors of the border towns of El Paso, Nogales, Ariz., and Yuma, Ariz. Under Secretary of Commerce for International Trade Francisco Sanchez and U.S. Customs and Border Protection Commissioner Alan Bersin also were present.

Napolitano said the Department of Homeland Security will deploy 250 more border agents and expects to have 300 more under their next budget if it's approved. She stated that Homeland Security is investing "millions of dollars in the side of commerce and trade" to improve infrastructure and technology along the border.

However, she added that there is a need to correct wrong impressions about the border region. Napolitano said border towns are safe for travel, trade and commerce. She noted that the total value of imports crossing the Southwest border was up 22 percent in fiscal year 2010, she said.

"There is a perception that the border is worse now than it ever has been. That is wrong. The border is better now than it ever has been," she said.

The perception that the violence in Mexico has spilled over to bordering U.S. cities is "wrong again," Napolitano said. Violent crime rates have remained flat or decreased in border communities in the Southwest, she said. However, she recognized that "there is much to do with (their) colleagues in Mexico in respect to the drug cartels" that are largely responsible for the unprecedented wave of violence in that country.

El Paso Mayor John Cook said his city has been ranked the safest city in the country of its size, despite being across the border from Ciudad Juarez, which is at the center of Mexico's drug cartel violence.

"The lie about border cities being dangerous has been told so many times that people are starting to believe it, but we as border communities have to speak out," Cook sad.

Napolitano cited a reduction of 36 percent in the number of illegal immigrant detentions, a key number to estimate the total of illegal border crossings, and the increase in trade as reasons to believe the situation along the border has improved.

"Numbers are in the right direction and dramatically so," she said.

Still, she stressed that she didn't come to El Paso "to run a victory lap" and that there "is much work to do."