US President Joe Biden said that the United States will not lift the sanctions it imposes on Iran, to compel Tehran to return to the negotiating table to discuss ways to revive the nuclear deal, while Iran insists that it will not return to its obligations unless sanctions are lifted.

In response to a question whether Washington would lift the sanctions first to bring Iran back to the negotiating table, Biden replied in a video clip published by the US "CBS" channel today, Sunday, in the negative.

After long negotiations, in 2015 the United States reached an agreement with Iran preventing it from possessing nuclear weapons, which was also signed by China, Russia, Germany, France and Britain, before it was ratified by the United Nations.

But former US President Donald Trump withdrew from the agreement in 2018, saying it was insufficient at the nuclear level.

Trump re-imposed sanctions on Tehran that were lifted in exchange for fulfilling its nuclear obligations, prompting Tehran to exceed these obligations.

Biden promised to return to the agreement, provided Iran first fulfills its obligations.

On Sunday, however, Iranian leaders reiterated that the United States should lift all sanctions before they commit again to the restrictions the deal imposed on their nuclear program.

For his part, Iran's Supreme Leader, Ayatollah Ali Khamenei, stressed that his country will not return to compliance with the nuclear agreement before the economic sanctions against it are fully lifted.

On Sunday, Khamenei said that the United States must lift all sanctions if it wants Tehran to reverse its nuclear steps.

"Iran has fulfilled all of its obligations under the 2015 nuclear deal, not the United States and the three European countries ... If they want Iran to return to its obligations, the United States must lift all sanctions first," he wrote on Twitter.