Relations between Iran and the European Union are at a "determining stage" after Tehran's nuclear deal with world powers in July, European Parliament chief Martin Schulz said on Saturday, according to AFP.
"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 Iranian counterpart 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 his government to also take steps towards lifting sanctions on Iran.
The EU and U.S. sanctions have proved very damaging, locking up billions in Iranian assets overseas and starving the oil-dependent economy of crucially needed technology and investment.
Schulz was in Tehran on a one-day visit at the invitation of the Iranian parliament, the first by a head of the European Parliament.
He also said Iran played a "key role" in regional stability, especially in Syria.
He made the same point after meeting President Hassan Rouhani.
"The Islamic Republic of Iran is an element of stability in a region full of instability," Schulz said, according to AFP.
"As a result of terrorism in Syria we are facing an influx of refugees in Europe. Right now our main and common goal is fighting Daesh," the Islamic State group (ISIS), he said.
European countries have reached out to Iran, mainly for business-related purposes, since the nuclear deal was signed.
Austrian President Heinz Fischer recently travelled to Tehran, where he met Supreme Leader Ayatollah Ali Khamenei, President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif, and also attended an economic conference on Iranian-Austrian relations.
And, in another example, France recently opened a business development office in Tehran seeking to renew once-strong economic ties with Iran after the July 14 nuclear deal.
Iran joined talks with world powers on Syria for the first time in Vienna last month in a drive to end the more than four-year conflict. The Syrian regime and the opposition were not represented.
Both Iran and Russia support Syrian President Bashar Al-Assad's regime, while Western powers have pushed for the leader to step down.
AFP contributed to this report.