"We are now at the implementation stage of this agreement and at the end of this stage a door can be opened for economic cooperation and positive economic development," he said at a news conference in Tehran with Iran's parliament speaker Ali Larijani.
The European Union last month announced it had adopted the legal framework to lift its sanctions against Iran, once Tehran has curbed its nuclear activities.
The EU announcement came shortly after President Barack Obama ordered the US government to also take steps towards lifting sanctions on Iran.
Schulz was in Tehran on a one-day visit at the invitation of the Iranian parliament, the first of a head of the European Parliament to the country.
He is also due to meet President Hassan Rohani and Foreign Minister Mohammad Javad Zarif.
At the news conference, Schulz also said that Iran played a "key role" in regional stability, especially in Syria.
Iran joined talks with world powers on Syria for the first time in Vienna last month in a drive to end the four-year conflict. The Syrian regime and the opposition were not represented.
But today, Larijani said that "reducing critical problems in the region to a person is a strategic mistake".
Russia in late September launched air strikes on Syria. Moscow says its strikes target the Islamic State jihadist group and other "terrorists", but the opposition accuses Russia of focusing on moderate and Islamist rebels.
"A plan should be devised to create a region free of criminal terrorist movements," Larijani said.