The session was called by EU Minister for Foreign Affairs Josep Borrell.
European Union foreign ministers held an emergency meeting on Friday at Brussels in an attempt to chalk out way to avert confrontation between Washington and Tehran.
Trump on Wednesday pulled back from the brink of war with Iran after having ordered the killing of a top Iranian general, to which Tehran responded with missile strikes on Iraqi bases used by U.S. forces.
On Wednesday, Boris Johnson has called for tensions to be eased in the Gulf but said the Iranian general killed by United States forces had British blood on his hands.
They also want to convince US President Donald Trump, who on Wednesday called on them to join him in withdrawing from the nuclear agreement, that they are tough-minded allies who will not be deceived by Tehran.
The agreement is created to halt Iran's nuclear program, but the country said on Sunday - following the assassination of top Iranian general Qassem Soleimani - that it no longer felt compelled to stick to its terms.
Jean-Yves Le Drian said if the regime carried on violating the 2015 deal restricting its weapons programme then it could become a nuclear power in just 'one or two years'.
France, meanwhile, has said it is still "committed" to the deal, and Boris Johnson reiterated his support in a phone call to Iranian President Hassan Rouhani on Thursday.
New sanctions were imposed on Iran following missile strikes by it on bases housing U.S. troops in Iraq.
Iran said on Sunday that it was stepping back from its commitments under the nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), that was aimed to prevent Tehran from developing nuclear weapons.
He further said that the massive demonstrations in condemnation of the American assassination of General Soleimani in various countries indicate the late Iranian commander's popularity and his leading role in regional stability and security.
He added Gen Soleimani, who was killed by a U.S. drone strike on 3 January, "had the blood of British troops on his hands", because he had "supplied improvised explosive devices to terrorists". It has, however, been damaged by Trump's decision to unilaterally abandon it in 2018 and to impose sanctions that have hurt Iran's economy.
The EU's diplomatic chief warned yesterday that it may not be possible to save the Iran nuclear deal, as the bloc's foreign ministers held emergency talks on the Middle East.
"We urge all our partners to continue on the path set out in the JCPOA and to create conditions for the resumption of its sustainable implementation", the Russian Foreign Ministry said in a statement.
Iran has gradually rolled back its commitment to the accord and the recent escalation of tensions between Iran and the US has dealt further blows to the pact.