In a series of tweets on Thursday, Zarif said: "JCPOA cannot be renegotiated, period.
"If 2021 is not 2015, it's not 1945 either. So let's change UN Charter and remove the veto so often abused by US.
"Let's stop posturing, which we both did 2003-2012 to no avail, and get down to implementing JCPOA which we both actually signed on to."
Zarif's remarks came after Wendy Sherman, US President Joe Biden's nominee for Deputy Secretary of State, called for a new "stronger" deal with Iran.
On Tuesday while speaking to his French counterpart Emmanuel Macron, Iranian President Hassan Rouhani said that the "JCPOA is by no means renegotiable, and the only way to protect and revive it is to remove sanctions by the US".
Iran's gradual retreat from its nuclear obligations is due to the US' 2018 withdrawal from the JCPOA as well as the "inability" of the UK, France and Germany to fulfil their nuclear commitments, he said.
As a result of the US' unilateral 2018 exit from the nuclear agreement, Iran has surpassed JCPOA-stipulated limits on its uranium enrichment level and on its stockpiles of heavy water and low-enriched uranium.
The Islamic Republic has also lifted JCPOA limitations on its nuclear research and development activities.
In December 2020, the country's Parliament passed the law of "Iran's Strategic Action Plan to Counter Sanctions" which obliges the government to further reduce the obligations under the 2015 nuclear deal unless the US lifts sanctions against the Islamic Republic.