LISBON--The Portuguese government said Tuesday it will cut spending in ministries and continue to lower the number of public workers to meet budget-deficit targets agreed with international creditors for next year.

Portugal will exit a three-year, EUR78 billion ($108 billion) bailout program next month, but lenders--the International Monetary Fund and the European Union--want to make sure the country won't slip back into overspending. They have imposed a deficit target of 2.5% gross domestic product for 2015, down from 4% this year. Deficit was close to 10% of GDP before the bailout program started.

While the country has struggled to cut the deficit in the first two years of the program thanks to a worse-than-expected economic slump, GDP and unemployment figures have improved since the second quarter of 2013, allowing the government to easily meet last year's targets.

The better economic performance also means that less austerity is required. Before Tuesday, the government estimated it needed to cut spending by more than EUR2 billion next year. Now that figure has dropped to EUR1.4 billion.

Finance Minister Maria Luís Albuquerque told reporters in a news conference that cuts in the number of public workers will continue to be made through retirement and mutual agreements. In addition, the government could consider imposing taxes on products that are harmful to health.

The government won't increase income taxes and it won't make further cuts on salaries and pensions, she added.

Key to Portugal maintaining investor trust after its bailout ends next month will be a long-term commitment to fiscal discipline. While the country still has two small bailout tranches to receive by June, it will have to rely solely on markets for financing from then on.

That wouldn't appear to be a problem. Demand for Portuguese debt has been increasing this year, driving bond yields to multiyear lows. The country's debt agency has been stepping up debt issuance, creating a EUR16 billion cash buffer sufficient to cover its financial needs for a year.

Last week, Fitch Ratings raised its outlook for Portugal to positive from negative, citing a strong economic recovery and falling budget deficit.

But the ratings agency also warned that any slippage in fiscal consolidation could make it change its mind. Fitch still considers the country's debt as junk, although a positive outlook could mean a rating upgrade at some point this year.

Write to Patricia Kowsmann at patricia.kowsmann@wsj.com

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