U.S. Ambassador Ken Salazar rejected accusations by Mexico’s president that the U.S. shares some responsibility for cartel violence in Sinaloa state.

Mexican President Andrés Manuel López Obrador says the United States is partially responsible for a wave of violence in the state of Sinaloa that has left dozens dead in the past two weeks, with bodies repeatedly found on public streets and highways.

Some 53 people have been killed and 51 others are missing in Mexico's western Sinaloa state since rival factions of the Sinaloa Cartel began clashing on Sept 9, local authorities said on Friday, with gruesome violence showing no signs of abating.

MEXICO CITY (Reuters) - The U.S. ambassador to Mexico on Saturday rejected President Andres Manuel Lopez Obrador's claims that the U.S. was "co-responsible" for violence in the western state of Sinaloa, where more than 50 people have died in an intra-cartel war this month.

Two warring factions of the Sinaloa cartel have clashed in the state capital of Culiacan in what appears to be a fight for power since two of its leaders were arrested in the United States in late July.

U.S. intelligence analysts suggest the conflict could last for years. The Drug Enforcement Administration reports the Sinaloa and Jalisco cartels have a presence in all 50 U.S. states, controlling global networks that dominate the fentanyl and methamphetamine trade.

Mexican leader says the U.S. bore some responsibility "for having carried out that operation" to arrest Ismael 'El Mayo' Zambada.