Striking a combative tone in her maiden speech to parliament, Meloni said her nationalist conservative coalition would make its voice heard in Europe and stressed her opposition to racism and discrimination.
Italy would continue to support sanctions against Russian President Vladimir Putin despite a squeeze on gas imports from Russia, Meloni said during a wide-ranging speech that lasted more than an hour.
"Giving in to Putin's blackmail on energy would not solve the problem, it would exacerbate it by opening the way to further demands and blackmail," Meloni said.
The head of the nationalist Brothers of Italy, Meloni, 45, swept to victory last month as part of an electoral coalition that included Forza Italia, led by former prime minister Silvio Berlusconi, and Matteo Salvini's anti-immigrant League.
Meloni said her government would offer financial support for families and firms hit by the energy crisis, warning that the high cost of this meant her administration might have to delay some of its more costly election promises.
"The context in which the government will have to act is very complicated, perhaps the most difficult since World War II," she said, adding that the economy could sink into recession next year as it battled rising inflation and disruption linked to the COVID-19 pandemic and Ukraine.
Meloni, who grew up in a working-class district of Rome, cast herself as an underdog who would defy negative forecasts about prospects for her government.
Meloni's party has neo-fascist roots but she told parliament that her government would fight any form of discrimination.
"I have never felt any sympathy or closeness to anti-democratic regimes. For no regimes, fascism included," she said.
"In the same way, I have always considered the (anti-Semitic) racial laws of 1938 the lowest point of Italian history, a shame that will taint our people forever."
Meloni criticised the European Union for not always being ready for challenges, notably the dramatic energy crisis now threatening households and businesses.
But she pledged that her four-day-old coalition government would stay loyal to EU accords while working for changes to some of them, including on monetary stability.
"To pose these questions doesn't mean being an enemy or a heretic but a practical" person, Meloni said.
On immigration, a key issue for her supporters, she said Italy would seek to stop people being smuggled across the Mediterranean and work with governments in Africa to help halt the migrant flows from the continent.
Meloni's supporters gave her a standing ovation after her 70-minute speech, with some chanting: "Giorgia, Giorgia".
The lower house will hold a confidence vote on the new government later on Tuesday, which Meloni should win comfortably.
A similar vote is expected in the upper house Senate on Wednesday.
with AP
