US Secretary of State Condoleezza Rice said on Wednesday that Mexico faced unprecedented difficulties in its fight against organised crime, amid spiralling violence including recent suspected drug cartel attacks on a US consulate.

"Mexico faces unprecedented difficulties in terms of crime and the links between crime and drugs, and obviously that have ? given our long, shared border ? significant implications for the United States as well," Rice said to journalists on the way to Mexico, where she arrived late on Wednesday for talks with her Mexican counterpart.

Merida Initiative

High on the agenda between Rice and Foreign Minister Patricia Espinosa is the Merida Initiative, a $400-million US anti-drug crime aid package signed into law in June by President George W. Bush.

Mexican officials, including President Felipe Calderon, have called for the rapid release of resources contained in the package ? mostly helicopters and surveillance airplanes ? and Rice is likely to hear a similar message privately during the two-day talks in the popular tourist resort of Puerto Vallarta.

"We consider this an issue for which there is urgency," Rice said on Wednesday. "I think it's urgent because of the security situation."

High security measures were in place in Puerto Vallarta, including the deployment of 60 police officers, following an 11 October attack on the US consulate in Monterrey, south of the Texas border. A second incident where shots were fired nearby led to a brief closure of the consulate.

Almost 4000 killed

Almost 4000 people have been killed in drug-related violence since Calderon took office some two years ago, despite a government crackdown involving the deployment of 36 000 troops across the country.

The violence includes gruesome beheadings, kidnappings and massacres.

More than 1000 have died in northern border areas including the volatile cities of Tijuana, across from San Diego, and Ciudad Juarez, further east, across from El Paso in the United States.

US drug chief John Walters said last week in Mexico City that drug-related violence was spilling across the Mexican border into the United States.

A Mexican proposal to decriminalise possession of small amounts of drugs and another to legalise marijuana were also expected to be discussed, as Mexican officials consider alternative methods for stemming drug crime.

Rice was due to join a private dinner with Espinosa and other officials late on Wednesday before further talks and a news conference on Thursday.