A pragmatist who engineered the country's landmark 2015 nuclear deal with world powers, Rouhani won the 2013 election by a landslide on a platform of ending the Islamic Republic's diplomatic isolation and creating a freer society.
"Despite four decades of the Islamic system and many promising achievements, people are still suffering chronic problems", he said when announcing his bid last week.
One big question is why Raisi would risk a run for the presidency if he has ambitions to become supreme leader as many speculate.
In the ceremony, held at Iran Helicopter Support and Renewal Company (IHSRC) in Tehran, President Rouhani unveiled Kowsar, the country's first jet aircraft used for training.
Though accurate public polling remains hard in Iran, Rouhani remains the favorite of analysts. But the oil-based economy's struggle to rebound since the lifting of sanctions as part of the nuclear accord could be exploited by Rouhani's hardline foes this time around.
In a new attempt to convince undecided voters and citizens disappointed with his policies, the Iranian President stressed that his government's economic performance was better than his predecessors' in recent years.More news: Pence On North Korea: 'Era Of Strategic Patience Is Over'
The upcoming vote will be seen, among other things, as a referendum on the nuclear agreement with world powers, under which Iran agreed to curb its uranium enrichment in exchange for the lifting of worldwide sanctions.
He will face frontrunner Ebrahim Raisi, who also registered on Friday, and is close to the Supreme Leader Ayatollah Khamenei.
All the candidates will be vetted by the Guardian Council, a 12-member panel half selected by the supreme leader and half nominated by the judiciary and approved by parliament.
Also in the same month, Secretary of Iran's Supreme National Security Council (SNSC) Ali Shamkhani underlined his country's continued progress and advancement in its defense and missile program, saying that the country is strongly opposed to foreign interference. Several former ministers and hardline former president Mahmoud Ahmadinejad are among those who have registered.
Within Iran's complex mix of clerical rulers and elected officials, Khamenei has the final say on all state matters. While observers have noted, in the past (indeed, since 2009), that the cancers were likely to prove fatal, there was evidence now that Iranian political and military figures viewed his situation now as grave. Trump said in January that Iran was "playing with fire" after the country tested a new ballistic missile. Security forces answering only to the supreme leader also routinely arrest dual nationals and foreigners, using them as pawns in worldwide negotiations.