"Hopefully before the end of this year certainly we would have the implementation day," Reuters quoted Araqchi as saying on Monday.
Araqchi made the remarks after meeting representatives of the Group 5+1 (Russia, China, the US, Britain, France and Germany) during the first Joint Commission under the Joint Comprehensive Plan of Action (JCPOA) in Vienna.
The Joint Commission, comprising representatives of Iran, the Group 5+1, and the European Union (EU), is tasked with implementing the terms laid down in the JCPOA and its annexes.
When asked whether Iran had started mothballing centrifuges, Araqchi said the process had not begun yet.
"We need an order by the president to the Iranian Atomic Energy Organization to start the job. That would be done after some preparations that we still need to do in the coming days. So it would soon start," he said.
On Sunday, Iran's Foreign Minister Mohammad Javad Zarif and the EU Foreign Policy Chief Federica Mogherini in a joint statement voiced their commitment to the implementation of the JCPOA.
“The EU today adopted the legislative framework for lifting all of its nuclear-related economic and financial sanctions. It will take effect on Implementation Day, simultaneously with the IAEA-verified implementation of agreed nuclear measures by Iran,” the statement said.