Addressing a cabinet meeting on Wednesday, Rouhani said the government will work hard to repair the damage and will rebuild the affected areas better than what they were, president’s official website reported.
The president said estimates show that the floods sparked by heavy rain across Iran in recent weeks have caused an estimated 400 trillion rials (about $2.9 billion) in damage, adding that the figure is likely to increase after the estimates of the damage in Khuzestan Province are released.
The Iranian president said the United States' reaction to the floods had revealed Washington's "vicious" nature.
Iran's Red Crescent has repeatedly complained that US banking sanctions reimposed last year make it impossible to receive donations from outside the country.
Washington "always claimed that it is on very good terms with the people of Iran (and) it is the Iranian government that it has a problem with," Rouhani said.
But by blocking aid to the Red Crescent, the US had given lie to that claim, he said.
"The heads of the American regime have revealed their true vicious and inhuman nature," he said.
The Iranian president thanked the countries that rushed to help Iranian people and government by sending humanitarian aid.
According to the head of the Iranian Red Crescent Society (IRCS), Kuwait, Germany, Azerbaijan, France, Pakistan, Turkey, Armenia, South Korea, and Japan as well as the World Health Organization have so far delivered humanitarian aid to Iran.
An Indian air freighter carrying an eight-ton cargo relief material also reached Tehran on Wednesday.
The aid compromised essentials like plastic sheets, blankets, dehydrated and canned food items and tents among others. The next consignment of the India’s humanitarian aid is scheduled to reach Iran via waterways shortly, a statement by India’s Embassy in Tehran said.
The International Federation of Red Cross and Red Crescent Societies (IFRC) said on Monday an estimated two million people need humanitarian assistance as a result of the massive floods that have swept across Iran.
The Geneva-based organization said it had launched an international emergency appeal seeking 5.1 million Swiss francs ($5.1 million) to expand support by the Iranian Red Crescent Society to an additional 30,000 families – equivalent to about 150,000 people.
On Sunday, Interior Minister Abdolreza Rahmani Fazli said 25 provinces and more than 4,400 villages across the country were affected by the floods.
Transport Minister Mohammad Eslami also said 725 bridges have been totally destroyed.
"More than 14,000 kilometers of roads have been damaged," he said
Iran’s worst floods in 70 years had killed at least 76 people and forced more than 220,000 into emergency shelters, officials said.
Officials have again issued flood warnings for the east of Iran with heavy rains that began on Saturday forecast to continue.