"Iran, as a country supporting global disarmament, invites the world to disarm and prevent proliferation," he told the state-run Irna news agency.
He said China has already agreed to attend the conference, which is scheduled to take place only days after a US-sponsored nuclear security summit in Washington, DC.
"The Chinese have welcomed the Islamic Republic's initiative and the idea of calling on the world to disarm and will take part in the Tehran conference."
Sunday's announcement comes three days after Beijing agreed to join international discussions on possible new sanctions against Iran.
Hu Jintao, the Chinese president, is due to attend the US nuclear summit on April 12.
China has previously been opposed to a new round of UN sanctions, with senior Chinese diplomats to the UN repeatedly saying diplomacy was their preferred route.
But US officials said last week that Beijing indicated a shift away from its previous reluctance during a conference call among the five permanent members of the UN Security Council and Germany, known as the "P5+1" group.
China's support, or at least acquiescence, is crucial to securing a new round of sanctions against Tehran, as it is a permanent member of the Security Council with the power to veto any resolution.
Some analysts say China will push to ensure any possible sanctions do not threaten its energy and trade ties with Iran.
A US draft proposal agreed with its European allies and passed on to Russia and China a month ago will form the basis of discussions on new sanctions.
Russia, like China, reluctantly backed three previous rounds of UN sanctions against Iran for refusing to halt uranium enrichment as demanded by five Security Council resolutions.
Iran rejects Western charges that its nuclear programme is aimed at developing a weapon, insisting that it is for peaceful purposes and intended only to generate electricity.