Italy's deputy prime minister, far-right League leader Matteo Salvini, on Friday condemned Donald Trump's conviction as political, saying the ex-president was a "victim of judicial harassment".

Salvini, whose party is a junior partner in Giorgia Meloni's government, offered his "solidarity and full support" for Trump, who was found guilty on all charges at his hush money trial in New York.

"Solidarity and full support for Donald Trump, victim of judicial harassment and a process of political nature," Salvini posted on X in English.

"In Italy, we are sadly familiar with the weaponisation of the justice system by the left, given that for years attempts have been made to eliminate political opponents through legal means."

He said he hoped the Republican, who is running again for president in November's elections, would win against Democratic incumbent Joe Biden.

"I hope Trump wins; it would be a guarantee of greater balance and hope for world peace," Salvini said.

Italy's other deputy prime minister, Foreign Minister Antonio Tajani, leader of the right-wing Forza Italia party, was more circumspect.

In a TV interview, he said it was up to Americans to decide who they wanted as president, saying that for Italy, "it makes no difference for us".

"Italy is an ally of the United States, not of this or that president," he said.