In a post on his Twitter account on Sunday, Araqchi added that the two "important events" in relations between Iran and the EU would take place at a time that the United States has imposed toughest sanctions against Tehran.
He noted that Head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi would attend the third seminar on peaceful nuclear cooperation in the Belgian capital.
The senior Iranian diplomat said the fourth round of high-level political talks would be chaired by Secretary General of the European External Action Service (EEAS) Helga Schmid and him, Presstv reported.
Earlier on Sunday, the AEOI chief left Tehran for Brussels to participate in the two-day seminar, due to kick off on Monday.
The two events will come for the first time since US President Donald Trump withdrew his country in May from the Iran nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), and decided to re-impose unilateral sanctions against Tehran.
Under the deal, reached between Iran and six major powers -- the United States, Britain, France, Germany, Russia and China -- Tehran agreed to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions.
The US administration hoped to get the other parties to the deal with Iran to likewise scrap the deal, but instead, they stressed that not only would they stick to the agreement, but they would also work to sustain it in the face of increased US pressure.
Iran has not left the landmark nuclear deal yet, but stressed that the remaining signatories to the agreement have to work to offset the negative impacts of the US pullout for Iran if they wanted Tehran to remain in it.
In March 2017, Iran and the European Union held a high-level seminar with the aim of promoting bilateral cooperation in the field of atomic energy.
The event, titled “International Nuclear Cooperation: Expectations and Responsibilities,” was held in Brussels with senior European and Iranian officials in attendance.