US Secretary of State Hillary Clinton says the US must take part of the blame for drug-related violence in Mexico.
Speaking as she arrived in Mexico, she said the US’s appetite for drugs and its inability to stop arms crossing the border were helping fuel the violence.
Her two-day visit comes a day after the Obama administration announced new measures to boost border security.
Some 8,000 people have died in drug-related violence in Mexico over the past two years.
On Tuesday, the White House unveiled a $700m (£745m) strategy that includes boosting security on the border, moves to stem the flow of illegal guns and drug profits from the US into Mexico, and steps to cut domestic drug consumption.
Our insatiable demand for illegal drugs fuels the drug trade
US Secretary of State Hillary Clinton
Mexico arrests ‘top drugs hitman’
Speaking to reporters accompanying her to Mexico City, Mrs Clinton said: “Our insatiable demand for illegal drugs fuels the drug trade.
“Our inability to prevent weapons from being illegally smuggled across the border to arm these criminals causes the deaths of police officers, soldiers and civilians.
“I feel very strongly we have a co-responsibility.”
She also acknowledged that US efforts to ban drugs had so far been unsuccessful in stopping the narcotics trade.
“Clearly, what we have been doing has not worked and it is unfair for our incapacity… to be creating a situation where people are holding the Mexican government and people responsible,” she said.
The BBC’s Stephen Gibbs in Mexico says these points have been repeatedly made by Mexico, which sometimes sees itself as the setting for an American financed and armed war.
‘Common future’
In a joint news conference with Foreign Minister Patricia Espinosa in Mexico City, Mrs Clinton stressed the importance to both countries of working together to build a “common future”.
See the Mexican cartels’ main areas of influence
Mrs Clinton said discussions with Ms Espinosa had been very productive and praised Mexican President Felipe Calderon for his “great courage” in tackling organised crime.
“The criminals and kingpins spreading violence are trying to corrode the foundations of law, order, friendship and trust between us,” she said. “They will fail.”
Mrs Clinton also spoke about the importance of trade between the two nations, as they sought recovery from the global economic crisis.
Immigration, climate change, energy issues and security were also on the agenda for the trip, she said.
Asked about a dispute between the two nations which began after the US stopped a pilot scheme which allowed Mexican trucks to use roads in the US, Mrs Clinton said only that she was aware of the dangers of protectionism.
Mexico said the decision earlier this month violated a free-trade deal between the countries and retaliated by imposing higher tariffs on some 90 American exports.
