As the Biden administration takes steps toward a renewed detente with Tehran, some of Washington’s Arab allies in the Middle East — who opposed the landmark multinational 2015 nuclear deal with Iran — look with mounting unease at the U.S. return to Obama-era policies following the about-face of the Trump years.

The United States is “going on overdrive to make the Iranians come to the table. All the Arabs … are sitting on the edge of their seat waiting to see the fate of the region,” said Mohammed Alyahya, chief editor of the Saudi state-owned broadcaster Al Arabiya English News and a senior fellow at the Gulf Research Center.

Although leaders of these nations have not commented publicly, Alyahya said that a return to the nuclear accord, known as the Joint Comprehensive Plan of Action, or JCPOA, “couldn’t be worse.”

In a major foreign policy speech that emphasized the need for global cooperation to tackle pressing problems, President Biden on Friday said the risk of nuclear “mistakes” makes it imperative to reengage in talks with Iran and world leaders to revive the Iran nuclear deal that Trump withdrew from after taking office.

The speech comes one day after a State Department statement saying the U.S. would accept an invitation from the European Union to attend a meeting between Iran and the five permanent members of the U.N. Security Council as well as Germany — known as the P5+1 — to discuss a diplomatic way forward on Tehran’s nuclear program.

At the United Nations, the Biden administration axed Trump’s controversial bid to invoke the so-called snap-back mechanism, which would reimpose U.N. sanctions on Iran. It also eased travel injunctions on Iranian diplomats that had all but restricted them to moving between their U.N. mission and the U.N.’s New York headquarters.

Taken together, the moves were a disavowal of the Trump administration’s “maximum pressure” policy, which had the U.S. abandon the JCPOA in 2018 and mount a harsh sanctions campaign on Iran and its regional allies in Lebanon, Syria, Iraq and Yemen.

Iran responded by announcing plans to increase its stockpile of nuclear fuel and to enrich uranium to 20% — a significant threshold above the cap of 3.67% but still far below weapons grade. It recently announced a Sunday deadline for the U.S. to lift Trump-era sanctions or it will prevent unannounced inspections of nuclear facilities and stop inspectors from accessing undeclared nuclear facilities.

In a virtual session of the annual Munich Security Conference, Biden signaled a commitment to reach an agreement, saying that “the threat of nuclear proliferation … continues to require a careful diplomacy and cooperation among us.”

“We need transparency and communications to minimize the risk of strategic misunderstanding or mistakes,” Biden said.

So far, progress on reviving the deal appears to hinge on either Tehran or Washington taking the first step.

Iranian Foreign Minister Mohammad Javad Zarif said in a tweet on Friday that the U.S. should act in compliance with the JCPOA and “unconditionally & effectively lift all sanctions imposed, re-imposed or re-labeled by Trump.”

“We will then immediately reverse all remedial measures,” he tweeted, ending his post with “Simple: #CommitActMeet.”

European leaders and officials Thursday welcomed a potential U.S. and Iranian return to JCPOA compliance. Later that day, after a virtual meeting among Secretary of State Antony J. Blinken and his European counterparts from Britain, Germany and France, a joint statement warned Tehran of violations that could jeopardize a “time of renewed diplomatic opportunity.”

That was a view shared in several quarters in Washington. Benjamin Friedman, policy director for Defense Priorities, a liberal group that advocates for renewed diplomacy with Iran, said in a statement the deal was important “less because of its overt nonproliferation aims than its overall effect on U.S.-Iran relations and foreign policy.”

“It limits the risk of a pointless war and reduces the futile and counterproductive U.S. military role in the Middle East,” he said.

That’s not how top U.S. allies in the Middle East would characterize the moment, especially Saudi Arabia, which considers Iran its nemesis in a regional battle for influence and which has long relied on U.S. forces to bolster its defense. Such allies contend that Tehran sees Washington’s diplomatic maneuvers less as goodwill gestures than concessions, said Mohammed Al-Sulami, head of the Riyadh-based International Institute for Iranian Studies.

“Iran is taking advantage of this haste on the part of the U.S. to get more, which is the lifting of sanctions. All it wants now is to help its economy,” he said.

Another common criticism here of the 2015 accords, which had Iran give up 97% of its nuclear fuel and adhere to limits on developing any future nuclear production in exchange for sanctions relief, is that negotiations excluded regional countries and didn’t address their concerns, Alyahya said.

One sticking point is Iran’s ballistic missile program, with Gulf countries demanding a cap on missile range. Another problem is Tehran’s support to paramilitary groups in the region, and its building of a network of pro-Iran factions that includes U.S. opponents such as Lebanon’s Hezbollah and Iran-supported militias in Iraq, Syria, Yemen and Afghanistan.

Alyahya pointed out that this week had seen a surge in incidents he blamed on Tehran, including a rocket attack on the northwestern Iraqi city of Irbil, where an Iraqi armed faction calling itself Caretakers of the Blood lobbed a volley of rockets, killing one civilian contractor and wounding a U.S. service member as well as several American contractors, authorities said.

Iranian help has also been instrumental to Houthi rebels in Yemen, who have recently prepared for a large-scale assault that threatens to overwhelm an important government bastion, the U.N. and other humanitarian groups have warned.

“The region has skin in the game, and these are the nations who are saying there are issues that are just as dangerous as the nuclear one,” Alyahya said.

In his Friday speech, Biden said there was a need to address what he called “Iran’s destabilizing activities across the Middle East,” and that the U.S. and its allies will also work to lock down fissile and radiological material to keep it out of the hands of terrorist groups.

“We are going to work in close cooperation with our European and other partners as we proceed,” he said.

Biden’s outreach to Iran comes as his administration has vowed a change of approach toward its regional allies. That includes a reappraisal of weapons sales to Saudi Arabia and the United Arab Emirates, which have mounted since 2015 with a bombing campaign as well as a land and sea blockade that has pushed Yemen to the brink of famine, rights groups say.