JUDY WOODRUFF: Finally tonight, trying to combat intensifying drug violence in his country, Mexico's president visits the White House.
Hari Sreenivasan has our story.
HARI SREENIVASAN: Four years of murderous conflict, 35,000 people killed, more than 1,100 just in the first two months of this year. This carnage is not happening in some far-off land, but on America's southern frontier, in Mexico.
Much of the violence happens along the border, stretching from Matamoros in the east, along the Rio Grande River, through Nuevo Laredo and Juarez, west to the Pacific Coast and Tijuana. The drug war there shows no sign of letting up, as Mexico's powerful cartels do battle with each other and Mexican authorities in broad daylight on city streets, and as President Felipe Calderon begins the fifth year of his fight against them, with the Mexican army and federal police.
FELIPE CALDERON, Mexican president (through translator): The criminals, the enemies of Mexico, try to infringe the laws and our democratic institutions.
HARI SREENIVASAN: Today, Calderon came to Washington to meet with President Obama. The drug war was topic A. on an agenda that included the ever-present issues of immigration and trade.
The two leaders are also seeking to repair damaged relations, a byproduct of diplomatic cables disclosed by WikiLeaks which showed American officials lacked confidence in Mexico's government and feared it too weak and corrupt to win the fight against traffickers.
Calderon shot back recently in an interview, voicing many Mexicans' belief that the U.S. will neither accept nor combat America's major role in fueling the violence. Insatiable American demand for drugs, especially marijuana and cocaine, is the backbone of the cartels' business. And they wage war with weapons smuggled from America into Mexico.
U.S. and Mexican authorities estimate that 90 percent of the weapons used by traffickers that could be traced come from the U.S. One of those guns, bought in Texas, was used to murder American immigration agent Jaime Zapata and wound a colleague two weeks ago as they drove to Mexico City.
Today, Homeland Security Secretary Napolitano said the U.S. would seek extradition of suspects now in Mexican custody.
U.S. PRESIDENT BARACK OBAMA: We are very mindful that the battle President Calderon is fighting inside of Mexico is not just his battle. It's also ours. We have to take responsibility, just as he's taking responsibility.
HARI SREENIVASAN: Presidents Obama and Calderon spoke to reporters this afternoon. And Mr. Obama pledged to combat the southerly flow of weapons along what has been dubbed the Iron River.
BARACK OBAMA: We have put more and more people behind bars for the transfer of weapons across the border into Mexico.
We recognize that it's not enough and that we've got to do more. Part of that job is to enforce the laws that are already on the books more effectively. Part of it may be to provide additional tools to law enforcement so that we can prevent the shipment of these weapons across the border.
HARI SREENIVASAN: For his part, Calderon acknowledged the delicate politics of gun rights discussions in the U.S., but said there was a way to make sure fewer weapons headed south.
FELIPE CALDERON (through translator): If we can find a means of sealing ports of entry along the border, through the use of non-intrusive mechanisms for detection, we could assuredly have the safe and secure border that both nations want. I think it's a way of ensuring security without affecting the Second Amendment rights of U.S. citizens and, at the same time, stopping the flow of drugs northbound, monies and guns southbound.
HARI SREENIVASAN: Felipe Calderon has one more year left on his presidential term.