"Participants also emphasised their commitment to preserve the JCPOA and discussed modalities to ensure the return to its full and effective implementation".
AgenciesTwo diplomatic sources said Britain, France and Germany had already held talks with Iran on Monday.
On Wednesday US State Department spokesman Ned Price reacted to the strategic document between Iran and China while speaking in a press briefing.
"We've been looking at options for doing so, including with indirect conversations through our European partners", Price added.
While the Biden administration has signalled a possible return to the 2015 agreement - which former president Trump left in 2018, slapping Iran with harsh sanctions - it has not made any actual steps in reviving the deal.
The online meeting will be chaired by the deputy secretary general and political director of the European External Action Service (EEAS) Enrique Mora on behalf of EU High Representative Josep Borrell.
In 2018, then President Donald Trump unilaterally withdrew the USA from the deal, which is aimed at reining in Iran's nuclear program.
But Biden has promised to rejoin the agreement on condition Tehran first returns to respecting the commitments abandoned in retaliation for Trump's decision.
The State Department did not immediately reply to a request for comment.
On Tuesday, Iran's Foreign Minister Javad Zarif slammed the Biden administration for the very same thing - pursuing the policies of the former United States commander-in-chief by punishing Iran's actions via sanctions, while two years ago, Biden himself criticized that approach.
The agreement sealed Saturday has triggered commentary among USA conservatives of a new anti-US "axis" and would have likely been sharply criticized by former president Donald Trump's administration.
He stated that the agreements "will ultimately allow Iraq to develop its energy self-sufficiency and, we hope, to end its reliance on Iran". "China has been cooperative in efforts to constrain Iran's nuclear program", he said.
It was created to prevent the Islamic republic from acquiring a nuclear arsenal by imposing strict limits on its nuclear programme and force it to remain exclusively civilian and peaceful.