In decrees that reverse restraints on naturalization put in place by former President Nicolas Sarkozy, Valls said he wanted to end the "strong heterogeneity" shown by the nation's immigration processing centers, France 24 reported Thursday.
Some of the 186 offices had a rejection rate 10 percent higher than the national average.
The changes will be instituted next week in eastern France, and could be applied nationwide by 2015.
Prefects, the highest representatives of the national government in the country's administrative regions, will no longer be solely responsible for deciding who gets accepted for naturalization. They will now be joined by a two-person committee the prefect has selected "for their ability to evaluate a person's path toward integration."
Another decree loosens the requirement for French fluency. Anyone who fails a written test will be interviewed in French to determine their language skills.
Immigrants typically must wait 14 years to become French citizens, said Pierre Henry, executive director of France Terre d'Asile, which lobbies for migrants' rights.
The opposition UMP party claimed the changes would make it easier for immigrants to enter the country.
"On the contrary, we think that becoming French must be the result of a successful journey of assimilation into the French community," the party said in a statement.