Centre-left opposition Democratic Party (PD) leader Elly Schlein on Tuesday voiced solidarity with Premier Giorgia Meloni after United States President Donald Trump slammed his one-time friend and ally of lacking the courage to help America in Iran and of criticising his "unacceptable" attack on Pope Leo XIV, with the PD chief saying the party would not accept attacks on Italy.

"We firmly condemn President Donald Trump's attack on Premier Meloni for dutifully expressing solidarity with Pope Leo," Schlein told the Lower House.

"We are adversaries in this Chamber," she added, "but we are all Italian citizens, and we will not accept attacks or threats against the government and our country."