PARIS—French President François Hollande’s government said Wednesday it will ramp up austerity measures in the next two years to stay on track with budget targets, despite a looming presidential election.

The French finance ministry said it would find an additional €3.8 billion ($4.31 billion) of savings this year and another €5 billion in 2017 to ensure France meets its pledge of getting the budget deficit under the European limit of 3% of economic output.

The belt-tightening indicates Mr. Hollande is opting for fiscal credibility rather than handing out sweeteners to taxpayers before the 2017 presidential election. Mr. Hollande is under pressure to clean up France’s finances after he diverged from his initial plans when elected in 2012 to get the deficit within the 3% limit in 2013.

The French finance ministry said France needs to make the extra savings to offset the costs of emergency plans to tackle unemployment and bail out the agricultural sector.

France’s public finances are also under pressure from lower-than-expected inflation. With inflation close to zero in the eurozone, the relative value of debt to nominal economic output is falling only very slightly. That means that governments need to come up with greater nominal spending cuts to meet their budget targets.

France’s consumer-price index will rise only 0.1% this year and 1% in 2017, mainly due to the slump in oil prices, the French finance ministry expects.

The finance ministry didn’t immediately give details of how it would curb spending in the next two years. But it said the measures would be enough to reduce the budget deficit to 3.3% of economic output this year and 2.7% in 2017, after 3.5% in 2015.

As a percentage of economic output, public spending will fall to 54% in 2017 from 55.3% in 2015, the finance ministry said.

The fiscal plans are based on an acceleration of economic output to 1.5% this year and next after 1.2% in 2015. Those forecasts are unchanged from France’s previous economic outlook.