US has to return, implement its obligations: Zarif

"The US left & violated the nuclear deal. So it's the US that has to return & implement its obligations," he tweeted.

"President Biden has a choice: Break with Trump's failed policies, or build on his failures. Building on his failures will only bring further failure," he added.

Speaking to CBS Evening News on Sunday, and asked whether the US would lift its crushing sanctions against the Islamic Republic "to get Iran back to the negotiating table," Biden answered simply "No."

"They'd have to stop enriching uranium first?" his interviewer probed, prompting Biden to nod in agreement.

The remarks are a repetition of similar claims made earlier by the White House spokesperson Jen Psaki, claiming that the ball is in Iran's court.

In a press conference on Friday, Jen Psaki, in response to a question about when US President Biden would like to try to come back to the table and get a deal on the Iran nuclear deal, said, "Well, that’s really up to Iran."

HJ/