Iranian government spokesman Ali Rabiei has warned France, Germany, and the UK against extending the UN arms embargo on Iran, signaling that doing so could spell the end of the Iran nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA).

"According to UN Security Council Resolution 2231, the import or export of weapons to the Islamic Republic is subject to obtaining prior permission for a period of 5 years. This restriction should automatically end in October," Rabiei told a news conference on Tuesday.

He called on the E3 to stop the policy of appeasing the U.S., which put the JCPOA and international peace "in danger".

Under the JCPOA, the UN must lift its arms embargo on Iran five years after the implementation of the nuclear deal. Despite its withdrawal from the JCPOA, the U.S. is pushing for the extension of the arms embargo on Iran, which is scheduled to expire on October 18.

The U.S. has also drafted a resolution calling for the extension of the arms embargo and has circulated it in the UNSC even as some permanent members of the council with veto power, like Russia and China, have strongly opposed extending the arms embargo. The council has yet to vote on the U.S. resolution. 

The U.S. officials have said that they would resort to the highly controversial option of triggering UN sanctions snapback if their resolution is vetoed in the Security Council.

On the other hand, Iran has made it clear that the extension of the UN arms embargo would lead to the death of the JCPOA.

In a tweet on May 3, Secretary of Iran's Supreme National Security Council Ali Shamkhani wrote: "#JCPOA will die forever by circumventing 2231 Resolution & continuing # Iran's illegal weapons sanctions. Sanctions' virus is the U.S. tool for survival of its declining hegemony. What will #EU do: Save dignity & support multilateralism or Accept humiliation & help unilateralism?".

The European signatories to the Iran nuclear deal have been caught in the middle on the UN arms embargo issue between Iran and the U.S. At the official level, the Europeans say they want to preserve the JCPOA, but at the same time, they voice concerns over what they call "major implications" of the planned lifting of the arms embargo on Iran.

"The E3 remains committed to fully implementing Resolution 2231 by which the JCPOA was endorsed in 2015. However, we believe that the planned lifting of the UN conventional arms embargo established by resolution 2231 next October would have major implications for regional security and stability," the foreign ministers of France, Germany, and the UK said in a joint statement on June 19, shortly after the International Atomic Energy Agency (IAEA) Board of Governors adopted an anti-Iran resolution on the same day.

The resolution, submitted by France, Germany, and the United Kingdom, was adopted by a vote of 25 to 2 with seven abstentions and was dismissed by Iran as "irresponsible and illegal."

UK Chargé d'Affaires to the UN Jonathan Allen echoed the same concern at the UN Security Council meeting on non-proliferation on June 30, saying the planned lifting of the arms embargo on Iran would have implications for the region.

Delivering a speech at the Security Council meeting, Allen claimed, "We believe that the planned lifting of arms restrictions on Iran in October would have major implications for regional security and stability."

The European parties to the Iran nuclear deal want to preserve the JCPOA. They also want to go along with the U.S. plan to extend the UN arms embargo on Iran in October. But Iran has made it crystal clear that the Europeans can't have their cake and eat it too.

As Rabiei said, there is no middle ground between adhering to the Security Council Resolution 2231 and not adhering to it. It's an either-or situation; you're either committed to it or not.

Therefore, now it's up to the Europeans to decide whether they want to save the Iran nuclear deal, which has been on life support since U.S. President Donald Trump walked out of it, or to join the U.S. in its efforts to extend the UN arms embargo on Iran. In light of Iran's clear warnings about the implications of the extension of the UN arms embargo, it seems that October will be the last chance for the E3 to save the JCPOA by fully implementing the UNSC resolution 2231.