Italy's best-known architect, Renzo Piano, has offered to donate a design for a bridge to replace the one that collapsed in his birthplace of Genoa this month, saying he cannot think about anything else after 43 people were killed in the tragedy.

The 80-year-old Piano - who designed the entrance to Valletta and the parliament building -  shot to fame with the design of the Centre Pompidou in Paris in the 1970s and decades later designed The Shard in London. He lives in France but still keeps an office near Genoa.

The project was announced after a discussion between the regional governor of Liguria, Giovanni Toti, and Piano.

"My commitment is above all moral, to make sure that the new bridge has the traits of Genoa, of our qualities and a little of our parsimony," Piano told reporters after the meeting.

"I can't think of anything else but that bridge."

Italy's populist government has pledged to strip the state concession to the toll road company that managed the bridge, and to have it rebuilt quickly, preferably by the state-controlled Fincantieri.

The collapsed bridge, completed in 1967, was seen as an avant-garde work of engineering at the time, and became a symbol connecting two sides of a city that snaked along the seashore.

"Renzo Piano voluntarily offered, as a competent Genovese, to give this new bridge project as gift to the city," Toti said. "We happily accepted the help, and he's already made a few proposals."