Biden will not allow Iran to have nuke, US says as talks hit critical phase

US President Joe Biden will not allow Iran to attain a nuclear weapon, the White House said on Friday as ongoing negotiations in Europe hit a "critical" period.

Spokeswoman Jen Psaki acknowledged there has been "some progress" in the Vienna-based talks, but said "if we don’t reach an understanding soon on a mutual return to compliance we will have to consider a different path forward."

"The bottom line is the president is not going to allow Iran to possess a nuclear weapon," she told reporters at the White House. "Several weeks ago the president asked his team to prepare a range of options. They have done that, and obviously our preference is always diplomacy."

The warning comes just two days after the State Department put a timeline of "weeks, not months" for negotiations to conclude productively. At stake is a mutual return for the US and Iran to compliance with the 2015 Joint Comprehensive Agreement.

The pact saw international powers, including the US, Russia, China, France, Germany, the UK and the EU, agree to prove Iran with billions of dollars in relief from biting economic sanctions in exchange for sweeping curbs on and inspections of the Islamic Republic's nuclear program.

Former US President Donald Trump unilaterally exited the agreement in 2018 in defiance of all the agreement's other participants, and re-imposed US sanctions that were lifted under the terms of the pact while issuing a slew of new economic penalties. He sought to have Iran agree to a more comprehensive agreement.

Iran, in retaliation, began to take steps away from its nuclear commitments under the agreement in a bid to have Washington lift its financial salvos.

Psaki continued to lay blame for the current state of affairs on the Trump administration, saying that its futile bid to bring Iran to the negotiating table to forge an improved pact only increased the likelihood that Iran will attain the bomb.

"This is no thanks to the decision by the former president to pull out of the Iran nuclear agreement, despite promises that they would agree on a stronger agreement, that Iran would not move forward. They’ve done exactly those things. Exactly those things they predicted would not happen have happened. That is why we are in the point we are in," she said.