Mr Rouhani, accused by critics of mishandling the crisis, took several cabinet ministers with him to Golestan Province, whose governor was dismissed on Saturday amid public outrage over his absence from work. He had been abroad when the disaster hit. At least 26 people have been confirmed dead and hundreds suffered injuries in the floods, officials said on Wednesday.
“We will rebuild Golestan just as it was before, and we will stand by your side,” Tasnim news agency quoted Mr Rouhani as telling a small gathering of villagers.
In a country more accustomed to drought, Mr Rouhani said the floods, caused by torrential rain, had affected 25 of Iran’s 31 provinces and that the scale of the disaster had overwhelmed emergency services in some areas.
Mr Rouhani was quoted as saying by the state media: ”The government will use all means and will compensate all those who have sustained damages to their houses, businesses and farms.”
Mr Rouhani’s hardline rivals have accused the government of doing too little, too late.
The head of the judiciary, Ebrahim Raisi, said on Tuesday that officials who mishandled the disaster and caused the death of civilians could face prosecution.
The severe damage caused by the floods has focused attention on shortcomings in Iranian infrastructure.
In the city of Shiraz, where 18 people died, officials said the floods occurred because an old waterway designed to siphon off excess water had been blocked by other construction.
The Revolutionary Guards had to blow up parts of a railway in northern Iran to facilitate the removal of water because there was no drainage channel under the raised structure.
The state-run meteorological organisation has also faced criticism, including from Mr Rouhani, for inaccurate weather forecasts and its late warning of flooding.
Tens of thousands of people have been displaced and thousands are being housed in emergency shelters provided by the government, state media said.
Iran is celebrating the Nowrouz new year holidays, a time when many families travel around the country, but rock falls and mudslides have blocked many roads and police asked people to avoid unnecessary journeys.
However, National Iranian Gas Company said its pipeline network had not been affected by the floods