But Luigi Di Maio offered no specific formula on how to end what could be a protracted political impasse.
Di Maio's anti-establishment movement was the single-biggest party to emerge from the March 4 parliamentary election, winning 32 percent of the vote. He said at a news conference that his lawmakers were willing to deal with parties on policy issues.
He was evasive, however, about what he'd be willing to concede during such negotiations and held firm that it should be he who leads the next government.
"We're unwilling to betray the popular will," said Di Maio, who at 31 would be Italy's youngest-ever premier and the first from the 5-Stars if he managed to create a government.
That will be tough since the party is far short of an absolute majority in Parliament and officially refuse alliances with other parties.
"We are projected toward government, but open to dealing" on policy "themes" with other political forces, Di Maio said.
He rejected oft-tried methods in the past to form governments from an array of Italian political parties, including cutting deals on divvying out ministries for coalition allies.
While the 5-Star Movement received the most votes of any single party in the election, a center-right bloc got 37 percent of the vote.
The leader of that bloc's biggest vote-getter is Matteo Salvini, whose euroskeptic League surged in the balloting. Salvini is insisting he get the mandate from Italy's president to try to cobble together a viable government. He and other members of his coalition, including former Premier Silvio Berlusconi, have vowed to never join forces with the 5-Stars in a government.
Asked, for example, if he could support Salvini's election platform for a 15-percent flat tax system, Di Maio was evasive.
The new Parliament meets for the first time on March 23. President Sergio Mattarella is expected to start consultations with main party leaders sometime in early April.
The Democratic Party, which has been leading Italy's government since 2013, suffered steep losses in the election. For now, Democratic leaders are insisting they'll stay in the new Parliament's opposition ranks and won't support either a 5-Star or a League-anchored government.
"There is a reasonable chance that the prospect of breaking the deadlock only improves after some initial, failed attempts to form a government," said Wolfango Piccoli, an analyst from London-based Teneo Intelligence.
"This means that it will likely take longer than the 50-60 days that are usually required to form a government" in Italy, Piccoli said, adding there's no guarantee of a positive outcome.
Di Maio, speaking to foreign correspondents, sought to defuse concerns that the 5-Stars are an extremist political force or determined to work against the European Union.
"I challenge anyone to say we have an extremist policy," he said, later adding: "We don't want to have anything to do with the extremist parties of Europe."
Arguing that Italian exporters suffer, Salvini has strongly lobbied for dropping sanctions against Russia over Ukraine.
Di Maio was vague on sanctions, saying only "Let's see if it's an opportune tool to use or not."
Frances D'Emilio is on twitter at www.twitter.com/fdemilio
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