Biden made his address to a global audience as his administration has begun reversing Trump administration policies.
The remarks by Mahmoud Alavi mark a rare occasion that a government official says Iran could reverse its course on the nuclear programme.
Iran's foreign minister alleged the killing of Mohsen Fakhrizadeh bore "serious indications" of an Israeli role, but did not elaborate.
US President Donald Trump reimposes tough, unilateral sanctions against Iran after exiting 'horrible' nuclear deal
Iranians are already seeing the effects of the sanctions, with Iran's rial currency losing around half its value since Trump announced the US would withdraw from the 2015 nuclear accord.
President Donald Trump withdrew the US from the Iran nuclear deal in May to pursue a maximum pressure campaign against Tehran's atomic programme.
Russian President Vladimir Putin too sounded critical of the US decision, saying the move may destabilise the Gulf region.
Noting that Israel had stayed out of Syria's protracted civil war, in which Tehran backs Assad, Netanyahu said increasing Iranian encroachment required "a new calculus".
Iran nuclear chief Ali Akbar Salehi specified that this was just the start of the production process.
The following is a selection of reactions from around the globe to Trump's biggest foreign policy move since taking office.
President Hassan Rouhani also said Iran could resume uranium enrichment without limit in response to Trump's announcement.
Despite calls from many of its allies, Trump announced Tuesday he was pulling the US out of the 2015 agreement.
Moscow condemned Trump's decision as proof of Washington's inability to negotiate alleging that US criticism of Iran's legal nuclear activity was just a smokescreen for settling political scores.
Syria said its ally would overcome what it called US "aggression", state media reported.
The deal was reached between Iran and six world powers -- Britain, China, France, Germany, Russia and the United States, imposing curbs to Iran's nuclear program in exchange for sanctions relief.
Trump said the 2015 agreement, which included Germany, France and Britain, was a "horrible one-sided deal that should never ever have been made."