"The country has no future if the debt does not drop," Centeno, who also leads the Eurogroup, said during a debate on the country's stability programme for 2019-2023.
"It is not possible to implement the sustainability of public policies without a trajectory of public debt reduction," he added.
Centeno pointed out that "today, public debt to GDP ratio is dropping and tomorrow it will start to drop in nominal terms."
He was responding to a question posed by Paulo Sá, an MP from the Communist party, who said that the government was looking to "receive a certificate for good student of the European Union" by committing to Brussels' "dictates."
The government plans to lower the public debt ratio from 118.6% this year to 99.6% in 2023.
In nominal terms, the same projections forecast public debt to reach €248.5 billion in 2020 and to drop from then on to eventually reach €243.6 billion in 2021.
Portugal signed a €78 billion EU-IMF bailout loan in 2011 and is often praised for its budget discipline combined with growth.
Under the Socialist government led by António Costa, which is backed by the Left Bloc and Communist party in the parliament, the country has managed to emerge from the debt crisis while casting aside harsh austerity, which critics say is unsustainable.