Mexico's federal attorney general said Thursday that more than 1,000 people have been killed in drug violence so far this year, but that he believes the worst is nearly over.

In an interview with The Associated Press, Attorney General Eduardo Medina Mora also said that 6,290 people were killed last year — the most specific government accounting yet of drug killings that doubled the 2007 toll.

Medina Mora said the world's most powerful drug cartels are "melting down" as they engage in turf wars and fight off a nationwide crackdown.

The government doesn't expect to stop drug trafficking, but hopes to make it so difficult that smugglers no longer use Mexico as their conduit to the United States.

"We want to raise the opportunity cost of our country as a route of choice," he said.

He applauded cross-border efforts that the U.S. Drug Enforcement Administration said culminated this week with the arrests of 755 Sinaloa cartel members and seizure of $59 million in criminal proceeds in the United States.

But Mexico's top prosecutor called for more U.S. prosecutions of people who sell weapons illegally to the cartels, as well as more efforts to stop drug profits from flowing south.

Mexico has spent $6.5 billion over the last two years, on top of its normal public security budget, on the fight against drugs, but that falls short of the $10 billion Mexican drug gangs bring in annually, he said.

Mexico has no choice but to press ahead with its fight, he said, predicting that violence will ease.

"I believe we are reaching the peak," he said, but added that the government won't achieve its objective "until Mexican citizens feel they have achieved tranquility."

While violence in Tijuana is down sharply from last year, killings have spiked in the largest border city, Ciudad Juarez. The city of 1.3 million across from El Paso, Texas, is now the most worrisome of a number of hotspots, Medina Mora said.

"But this is not reflecting the power of these groups," he said. "It is reflecting how they are melting down."

About 90 percent of the dead were suspected drug traffickers, and most of the rest were police and soldiers, Medina Mora said. Innocents caught in the crossfire account for about 4 percent of the toll, he estimated.

Medina Mora also said since the crackdown began in 2006, the price of cocaine has shot up by 100 percent in the United States, while its purity has dropped by 35 percent. And he said the government crippled Mexico's methamphetamine trade by banning precursor chemicals from its territory.

"The raw material is not here anymore" he said.