The Eurpean E3 condemned Iran’s action to reduce monitoring by the UN nuclear watchdog, while Washington said it would not necessarily hamper the Vienna talks.

France, Britain and Germany condemned on Thursday steps taken by Iran to essentially remove all the monitoring equipment installed by the International Atomic Energy Agency (IAEA) under the 2015 nuclear deal, saying the move cast a doubt on Tehran's will to revive the accord.

"These actions only aggravate the situation and complicate our efforts to restore full implementation of the JCPoA (nuclear deal)," the three countries said in a statement. "They also cast further doubt on Iran’s commitment to a successful outcome."

Unlike a joint statement made with the United States on Wednesday, Washington did not sign up to Thursday's statement.

The four Western powers who signed the 2015 nuclear agreement with Iran tabled a resolution critical of Iran this week at a meeting of the IAEA board of governors in Vienna after the UN watchdog’s director Rafael Grossi submitted a report saying Tehran has been stonewalling in an investigation of its past nuclear activities.

However, US officials on Thursday came up with their separate statements critical of Iran but saying that ultimately the safeguards and IAEA monitoring issues are “separate from the JCPOA.”

“The Board spoke to Iran's safeguard obligations, which are separate from the JCPOA. We are ready for a mutual return to full compliance immediately,” Rob Malley, US Special Envoy for Iran tweeted.

His statement that Iran’s safeguard obligations are separate from the JCPOA raised eyebrows, as Iran’s dismantling of monitoring equipment on Thursday was directly related to JCPOA.

The former Director for Countering Iranian Weapons of Mass Destruction for the White House National Security Council, Richard Goldberg tweeted, “It strikes me as an obvious question to ask any senior official: Can Iran be in full compliance with the JCPOA while remaining in non-compliance with the NPT?”

But Malley’s remark simply followed a statement by National Security Advisor Jake Sullivan on Wednesday that said, “Iran’s issues with the IAEA and efforts to revive the 2015 deal are “on separate tracks, and that’s how we’re going to proceed.”

This in effect means that if Iran continues its non-cooperation with IAEA regarding its past secret nuclear activities, that will not interfere with a new deal.

The question arises if such a US position undercuts the UN nuclear watchdog’s authority not only in relation to Iran but in the bigger picture of global non-proliferation efforts.

Meanwhile, Iranian officials remained defiant as they annouced they are speeding up uranium enrichment, with more advanced machines.

The Wall Street Journal Editorial Board in a column on Thursday said, “There are few good options when dealing with rogue states that have or want the bomb, but rewarding Iran for its malign behavior is easily the worst. It’s all the more remarkable that the Iranians now seem to prefer humiliating the White House over taking the generous concessions apparently on offer.”

US lawmakers, skeptical of the Biden Administration’s Iran policy, will also take a dim view of developments this week, especially Tehran’s decision to turn off IAEA’s monitoring equipment and warnings that Iran now has enough fissile material to race for a bomb almost immediately.

The Democratic chairman of the Senate Foreign Relations Committee, Sen Bob Menendez said Wednesday, “Iran now has enough uranium to produce a nuclear weapon. This latest milestone returns us to a familiar question: At what point will the Administration acknowledge that Iran’s nuclear advances make a return to the 2015 JCPOA not in the United States’ strategic interest?”