The government in Mexico has pledged to deploy more security forces and boost intelligence in Tamaulipas, one of the country's most dangerous states.
Mexican Interior Minister Miguel Angel Osorio admitted that the government had not done enough to deal with insecurity in the north-eastern state.
But he promised that a "new phase" against powerful drug cartels would restore peace there.
Last week, Mexican intelligence chief Salvador Haro Munoz was killed there.
His car was ambushed by armed men in the state capital, Ciudad Victoria.
Mr Osorio announced that the state would be divided into four regions, each with an army or navy officer in charge of implementing the government's security plan.
"We will strengthen surveillance at ports, airports, customs and border crossings, as well as the major land routes," he told a news conference.
Mr Osorio said security forces would "patrol 24 hours, every day of the week, in main urban areas", and would conduct reviews of local police forces to eradicate corruption.
He also admitted that, despite some "significant" government successes against the cartels, "these are not enough".
On Sunday, security officials said one of the founders of the Zetas cartel, Galindo Mellado Cruz, was killed in a gun battle in Tamaulipas.
The Zetas, which first served as enforcers for the Gulf cartel, have since split off and have been fighting a turf war against their former ally.
Dozens of people have been killed in recent weeks in the border state, which is criss-crossed by drug-smuggling routes to the United States.
The city of Nuevo Laredo, along the border with Texas, is a major hub for trade between Mexico and the US.
Since he came into office in December 2012, President Enrique Pena Nieto has also sent federal forces to deal with growing drug-related violence in the state of Michoacan and the State of Mexico, near the capital, Mexico City.