The increase would triple the number of troops and federal police officers operating there as part of President Felipe Calderon's offensive against drug traffickers.
Ciudad Juarez Mayor Jose Reyes Ferriz said the added troops would give the military a higher profile by taking control of police functions, including street patrols. Currently, soldiers tend highway checkpoints, guard crime scenes and take part in special operations, such as house searches.
The city is without a police chief. Roberto Orduña Cruz quit last week after several officers were slain and someone posted threats saying more would be killed unless he stepped down.
On Wednesday, top Mexican security officials traveled to Ciudad Juarez to reassure local leaders and vowed to significantly boost the federal presence.
A little more than 2,000 soldiers and 425 federal police officers are assigned to Juarez in addition to local police, army spokesman Enrique Torres said. He said the reinforcements could begin to arrive in two weeks.
The move would represent a continuation of Calderon's strategy of relying on the army and federal police to counter drug-trafficking gangs in the country's main smuggling corridors. He had deployed 45,000 soldiers and 5,000 police officers across the nation as part of the crackdown, launched two years ago.
The offensive has sparked shootouts between soldiers and traffickers and triggered vicious fighting between drug gangs that has propelled the country's fast-climbing death toll. More than 6,000 people were slain in 2008, and the figure has exceeded 900 this year, according to unofficial tallies by the news media.
Ciudad Juarez, which had about 1,600 killings last year, has been on edge over the police chief's resignation and threats that appeared over the weekend against the mayor.
Reyes and other officials have described the police slayings and threats as "acts of terrorism."
In a radio interview Thursday, Reyes said the city's 1,600-member police force was too small even before officers were ordered to double up in patrol cars after the recent threats. A beefed-up military contingent will help combat other crimes, such as robberies, kidnappings and extortion, the mayor said.
Reyes has vowed to continue trying to clean up the city's corruption-laden police force, which, like many in Mexico, has been infiltrated by drug smugglers.