In a break from recent criticism of Brussels, Renzi gave close alignment with the EU an endorsement Tuesday while addressing the lower-house Chamber of Deputies, just before the body gave his new government the vote of confidence it needed to formally take power by a 378-220 margin.
The government led by his center-left Democrat Party -- Italy's fourth in little more than two years -- had already won the approval of the Italian Senate.
Although he gained popularity by campaigning against unpopular EU-mandated budget austerity rules, Renzi dropped that tone in Tuesday's speech an instead concentrated on defending Italy's close ties with Brussels in remarks seemingly aimed at the populist Five Star Movement.
That group and other right-wing eurosceptic parties seem poised to make significant gains in May's European Parliament elections.
The new prime minister said those who oppose membership within the bloc are wrong because they ignore Italy's heritage as one the EU's founding members, the business daily Il Sole 24 Ore reported.
"To continue to think that the troubles of Italy are derived from the EU means not only to deny the evidence of the facts, but to also to betray the institutional history of this country that has helped to build Europe," he said.
Europe, he asserted, "is not our enemy, because there is no Europe without Italy."
With Italy set to assume the six-month rotating presidency of the European Council in July, Renzi indirectly refuted remarks once made by former Prime Minister Silvio Berlusconi, who dismissed the job by saying "half of it is purely honorific."
"We think of the EU presidency as half an enormous opportunity -- we do not think it is a formality," the new PM said.
At the same time, he also asserted the EU must be reformed, saying enthusiasm for the bloc is waning because of its tendency to micromanage and its role in enforcing unpopular deficit-reduction goals through austerity measures.
Without offering any specifics, Renzi said Italy would take the opportunity of the EU presidency to be more assertive.
"Today, Europe does not give rise to hope because we have let the debate devolve into only commas and percentages," he said. "We want a Europe where Italy is not going to just toe the line on what to do but make an important contribution, because without Italy there is no Europe."
To play the "leading role in Europe it deserves," Italy, Renzi said, must "roll up its sleeves" to carry out the internal changes he has called for, including reforms of the country's electoral law and bicameral Parliamentary system, which has been held responsibility for the country's political instability.
Renzi, however, made no mention of his previous calls for breaking EU budget austerity rules in order to fund an ambitious set of reforms. Italy trails only Greece in terms of its budget deficit at 133 percent of gross domestic product.
Olli Rehn, the EU's economic chief, said Tuesday in Strasbourg, France, he is "convinced that Italy will remain committed to the European treaties," Market News International reported.