"We will not deviate by one iota from our target of improving our public finances," she told RTL radio.
The French deficit currently stands at 5.7 percent of gross domestic product and the government has vowed to reduce it to 4.6 percent of GDP next year and to 3 percent in 2013.
Pecresse said that if extra efforts were needed to reach the 4.6 percent target, then "we will make extra efforts."
The International Monetary Fund said late last month that France would probably need extra action to cut its public deficit in 2012 and 2013 as falling growth threatened to complicate economic recovery.
It said that without further efforts France was set for a public deficit of 3.8 percent of output in 2013, above both the EU three-percent limit and France's forecast.
The IMF forecast that growth in France, the eurozone's second-biggest economy, would slow in 2012 to 1.9 percent from 2.1 percent this year. This was sharply lower than the French government's 2012 forecast of 2.25 percent growth.