Mattarella began his visit in Modigliana, in the province of Forlì-Cesena, one of the towns worst affected in the disaster.
Later in the day he met with volunteers in the city of Forlì and then with communities in Cesena, Ravenna and Lugo, before ending the visit in Faenza at a meeting with local mayors.
“You will not be alone in the reconstruction, which must be rapid,” the head of State said in Forlì.
Mattarella stressed that the reconstruction effort is important for the whole country, not just the north-eastern region itself.
“This is a challenging and difficult time,” he said.
“I have seen how much needs to be done, with courage and commitment, and I know that you will succeed because you have that drive in these areas.
“There is a need for reconstruction. It is a national necessity and you can be sure that there will be constant support.”
Mattarella told volunteer relief workers that they are “an example”.
“I have no words to thank you,” he said.
“What you have done is of extraordinary importance, it is an example of solidarity and common commitment and generous availability,” he continued.
One of the volunteers then presented the head of state with an orange safety jacket.
“This is a tribute, it is a protection for all of us and we want to share it with you,” he said.
Members of farmers’ association Coldiretti also presented the President with a basket of fruit and vegetables salvaged from the emergency.
The basket, containing lettuce, garlic, radishes, artichokes, cucumbers and asparagus, among other products.
Coldiretti said buying local agricultural and food products is the best way to support the local population and save the estimated 50,000 jobs in agriculture and food processing that are now at risk as a result of the floods.
Following his visit to Forlì, Mattarella travelled to Cesena, where he met with volunteers at a collection centre for basic necessities serving local residents affected by the floods.
Cesena Mayor Enzo Lattuca introduced the president to a man who had rescued a family by canoe.
“Thank you for your commitment, for what you did, and also for your inventiveness,” Mattarella said.
A woman coordinating relief in Cesena thanked the president for donating the Paul VI International Prize money to the John XXIII community working for the disabled, the homeless and other vulnerable groups whose facilities in Emilia Romagna have been damaged by the deadly floods.
“We will not forget,” the woman said.
Mattarella received the prize from Pope Francis on Monday.
Civil Protection Minister Nello Musumeci, meanwhile, said on Tuesday that it is “too bad” no-one from the government has been invited to accompany Mattarella during his visit.
“I am glad the President of the Republic is also in the flooded areas,” Musumeci told Rainews24.
“It’s too bad that there is no-one from the government to explain the critical issues to the Head of State, no one was invited,” he added.
“It doesn’t matter, the important thing is to get to the results,” Musumeci said.
ANSA