Politicians across Italy's political spectrum condemn Washington violence by rioters supporting Trump.

Italian premier Giuseppe Conte has condemned the violent scenes in Washington, where rioters supporting US president Donald Trump stormed the Capitol building.

The action forced the suspension of a joint session of Congress to certify president-elect Joe Biden's electoral victory, and has resulted in the deaths of four people.

Conte said he was watching the events unravel in Washington with "great concern."

"Violence is incompatible with the exercise of democratic rights and freedoms," he wrote on Twitter: "I am confident in the strength and robustness of the institutions of the United States."

I am following what is happening in #Washington with great concern. Violence is incompatible with the exercise of democratic rights and freedoms. I am confident in the strength and robustness of the institutions of the United States. #CapitolHill

— Giuseppe Conte (@GiuseppeConteIT) January 6, 2021

Italy's foreign affairs minister Luigi Di Maio described the events in Washington as "very serious," calling it a "real disgrace to democracy, an attack on the freedoms of the American people."

Di Maio said: "We strongly condemn all forms of violence, in the hope that there will be an orderly and peaceful transfer of power as soon as possible."

Quanto sta accadendo a Washington in queste ore è gravissimo. Un vero e proprio sfregio alla democrazia, un attacco alle libertà del popolo statunitense. Condanniamo con forza ogni forma di violenza, nell’auspicio che ci sia quanto prima un passaggio di poteri ordinato e pacifico

— Luigi Di Maio (@luigidimaio) January 6, 2021

The head of the right-wing Lega party, Matteo Salvini - considered the Italian leader closest to Trump - distanced himself via Twitter: "Violence is never the solution, never. Long live Freedom and Democracy, always and everywhere".

La violenza non è mai la soluzione, mai. Viva la Libertà e la Democrazia, sempre e dovunque.#Washington

— Matteo Salvini (@matteosalvinimi) January 6, 2021

Nicola Zingaretti, leader of the centre-left Partito Democratico (PD) described the chaotic scenes as "dramatic, the likes of which we thought we would never see," adding: "this is where political extremism takes us."

Mai avremmo pensato di vedere negli Usa immagini di questo tipo.

Tutti vicini alla forza della democrazia americana per difenderla da questi attacchi.

Ecco dove porta l’estremismo in politica #Trump #Washington pic.twitter.com/UmRNAVHTN1

— Nicola Zingaretti (@nzingaretti) January 6, 2021

Former Italian premier Enrico Letta attacked Trump directly: “What is happening at the Capitol Building in Washington is proof that Trump is a coup leader. He should be treated as such.”