Iranian supreme leader Ayatollah Ali Khamenei has demanded "action, not words" from the Joe Biden administration to show it is sincere about reviving the nuclear deal.

Iran and the United States remain at odds over who should take the first step to revive the accord. Iran says the US must first lift the sanctions imposed by the Donald Trump administration, while Washington says Teheran must first return to compliance with the deal, which it began violating after the Trump administration launched its self-described "maximum-pressure" campaign against the country.

Teheran stopped fulfilling some of its obligations under the deal in retaliation for the Trump administration's unilateral move to reimpose the sanctions on Iran that had been lifted under the 2015 deal.

Iran has now said that it will ban short-notice inspections by the United Nations nuclear watchdog next week unless the Biden administration begins reversing the sanctions. Such inspections are mandated under a 2003 International Atomic Energy Agency protocol that Iran agreed to honor under the 2105 deal.

A US State Department spokesman said Teheran should refrain from taking steps that would impact the IAEA assurances, saying that "the path for diplomacy remains open".

But that remains an idle invitation until the Biden administration unlocks the gate. So far, all that has been forthcoming from it is "nice words and promises" without any action to back them up.

Both parties should refrain from making any reckless moves that will only further compound their standoff, and both need to accept that they will have to make concrete moves if they are to move forward and revive the Iranian nuclear deal in full.

But since the current standoff was initiated by the actions of the Trump administration, the onus is on the Biden administration to show there has been a sea change in Washington's thinking. It should take the initiative to demonstrate the sincerity of its words, and get the ball rolling.

The Trump administration's capricious moves have not only taken a toll on the common aspirations for a world free from nuclear threats, but also greatly eroded Washington's credibility on the world stage.

As the world's sole superpower, the US has an unshirkable responsibility to join the rest of the world in making positive contributions to the global nuclear non-proliferation cause.

If Biden really wants to repair the damaged image of the US, rejoining the Iranian nuclear deal would be a good way to start.