President Hassan Rouhani has urged Iran's clerics to be more tolerant of the internet and new technologies.
In a speech broadcast on Iranian television, Mr Rouhani said it was vital that the younger generation had access to the internet.
The president, who was elected in 2013, has vowed to support greater media freedom but has faced opposition.
Last week, prominent Iranian cleric Ayatollah Makarem Shirazi said mobile internet was "immoral and unlawful".
Conservative clerics oppose introducing mobile broadband services, saying they allow immoral images to be shared freely and more easily.
In recent weeks the government has awarded 3G licences to three mobile broadband companies, but experts say the proportion of Iranians using the service is still low.
Speaking on Monday, President Rouhani insisted the internet was crucial to connect with the world of science, saying: "We cannot close the gates of the world to our younger generation".
"If we do not move towards the new generation of mobile today and resist it, we will have to do it tomorrow. If not, the day after tomorrow," he said.Facebook ban
BBC Middle East analyst Sebastian Usher says President Rouhani's comments will resonate in Iran, but it is unclear if they will carry any real weight.
Iranians will be waiting to see if his latest statement of intent produces real change in the face of the usual resistance, our correspondent adds.
Iran's government cracked down on media freedom and internet access after widespread protests against the country's leaders in 2009, banning online services like Facebook, Twitter and YouTube.
Since then, many Iranians have grown used to bypassing censorship controls by using proxy servers or other online tools.