Mexico's growing drug violence is now considered a "national security threat" by the United States, as the wave of drug-related killings and attacks in Mexico continues to mount.

There is a growing worry among U.S. officials that the bloodshed will spill over into the United States as Mexican authorities struggle to curb power of the drug cartels. 

Convoys of Mexican troops arrive in the border city of Ciudad Juarez.

The soldiers are being deployed to end the drug violence that has left hundreds of people dead in the city.

Yet the power of the cartels has grown throughout Mexico -- raising fears about the country's future stability.

While few expect Mexico's political stability to be threatened, Latin American expert Peter DeShazo says the country does face a serious problem. "It's a law enforcement problem but it's a very serious one because the level of the violence is extremely high," he said. "It's unprecedented and the resources available to the drug cartels is extraordinary."

And they have laid siege to authorities in Mexico's border cities, carrying out attacks with highly sophisticated weapons -- most purchased in the United States and smuggled into the country.

Mexican authorities say they have seized thousands of guns from the cartels.  And Mexican President Felipe Calderon wants Washington to do something about it.

"We've seized, in these two years, more than 25,000 weapons and guns and more than 90 percent came from the United States," he stated.

What is happening in Mexico, some experts say, is similar to Colombia in the late 1980's and early 1990's, when powerful drug cartels carried out assassinations and otherwise terrorized the country

Colombia was able to eventually crush the major cartels, DeShazo says, but it took time. "In the end, the Colombians were successful in dismantling the Medellin and the Cali cartel because they mobilized their resources and they got help from the United States," he said.  "But mostly it was the Colombians themselves that were able to do it."

There were 6,000 drug-related killings last year in Mexico and, so far, this year is bloodier.  And as the cartels continue their attacks, there is growing concern in the United States that the violence may spill across the border.

In describing the cartels as a national security threat recently, U.S. Attorney General Eric Holder said Washington is ready to help. 

Other U.S. officials, such as David Johnson of the State Department's Narcotics and Law Enforcement Bureau, are praising Mexico's efforts. "We think it's a challenge the government of Mexico is taking seriously," he said. "And they are taking the steps that are going to be necessary to get their hands around this."

But as in Colombia, crushing the cartels in Mexico could take years.