President Joe Biden will not race to renew a nuclear deal with Iran before June elections widely expected to see the rise of a more hardline president in Tehran, a US envoy said in an interview released Wednesday.

"We don't intend to base the pace of our discussions on the Iranian elections -- the pace will be determined by how far we can get, consistent with defending US national security interests," Rob Malley, the State Department pointman on Iran, told Axios.

"In other words, we won't rush or slow things because of the Iranian elections."

A number of supporters of diplomacy with Iran have called for renewed efforts before the election and the exit of President Hassan Rouhani, who staked his legacy on a 2015 denuclearization agreement that is on life support.

Some experts, however, counter that Ayatollah Ali Khamenei ultimately calls the shots in Iran and that a new president would at most change the optics.

Biden has sought to return to the 2015 agreement, which promised Iran sanctions relief but was trashed by former president Donald Trump, who imposed sweeping measures to hurt the Iranian economy and challenge Tehran's regional role.

Iran has so far balked at US overtures for talks, saying that Biden must lift sanctions before Tehran returns to full compliance with the nuclear deal by reversing steps it took to protest Trump's actions.