Biden says he won't lift sanctions on Iran to bring country back to negotiating table

"No," Biden said when asked by CBS' Norah O'Donnell if he would make the move to start negotiations, nodding when she asked in a newly released interview clip if the country must stop enriching uranium first. The interview is set to air in full on CBS later Sunday.

The President has said the US will rejoin the Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action, once Tehran fully complies again with the pact. Iran's position is that because the US left the agreement in 2018, Washington should make the first move by removing the crippling sanctions former President Donald Trump liberally imposed on Iran's leaders, on individuals and the economy, and for terrorism. Iran has increasingly breached its obligations under the nuclear deal after the Trump administration withdrew the US from it.

Iran's Supreme Leader Ayatollah Ali Khamenei said Sunday the US "must lift all sanctions" if it wants Tehran to return to the deal. Foreign Affairs Minister of Iran Mohammad Javad Zarif told CNN's Fareed Zakaria on Sunday that the US is the one who needs to return to the pact and that Iran never left it.

"It is very clear, it was the United States that left the deed. It was the United States that violated the deed. It was the United States that punished any country that remained respectful and compliant with the deed," Zarif said on "GPS." "It is for the United States to return to the deed to implement its obligations. Iran never left the deed."

Tehran's Parliament passed legislation on December 2 that requires significant increases in its nuclear activities at regular intervals if Iran's demands for sanctions relief, including on its banking and oil sectors, are not met.

Tehran announced in January that it had resumed enriching uranium up to 20% purity, far beyond the limits laid out in the 2015 nuclear deal.

Nuclear officials have also increased enrichment capacity at the Natanz facility. And on Monday, Iran aired video footage of what it claimed was the "most powerful" rocket engine using a system that could launch long-range missiles capable of endangering US allies in Europe and the Middle East or the US itself.