Valls was visiting the Netherlands for talks with Dutch counterpart Mark Rutte on how to kickstart the continent's economy.
"I want to tell you that we're absolutely determined to carry through our reforms," Valls said after Dutch complaints that Paris was breaking the European Union's spending rules.
France has said that next year's deficit — the shortfall between revenue and spending — will hit 4.3 percent of annual economic output, far above the EU's 3.0 percent ceiling.
Valls said Paris was committed to reducing public spending while "turning its back on political convenience".
It planned to save €21 billion ($26 billion) in 2015 "because we respect the rules of the game" in the eurozone and that France "had a commitment to ourselves".
Valls stressed however that it was a tough target to make with slow economic growth.
Brussels has written to France to demand explanations for the overshoot, according to a letter confirmed by President Francois Hollande this week.
France shocked its European partners in September by going back on a pledge to get its deficit to below the three percent ceiling by next year.
Instead, it pushed back this target to 2017 — the year of the next French presidential election — putting the eurozone's second-largest economy on a collision course with Brussels.
Speaking at a press conference in The Hague, Valls set to allay fears about France's obligation to EU rules.
"France is not Europe's sick man," Valls told reporters.
"My government has undertaken unprecedented structural reforms… but no area is immune," he said.
"We want to comply with European rules," Valls added.