The lead US envoy on international negotiations with Iran to limit Tehran’s nuclear program will head to the United Arab Emirates, Qatar and Saudi Arabia in a few days to discuss backup plans with Washington’s allies should the negotiations fail.

During a think-tank event in Washington on Wednesday, Special Envoy Rob Malley struck a cautious tone in discussing the Biden administration’s ambitions to returning to a nuclear agreement with Tehran.

“Everything we hear from our partners … about their concerns they have about Iran’s nuclear program, all of those have been not only exacerbated but created by the withdrawal from the JCPOA,” Malley said at an event hosted by the Carnegie Endowment for International Peace, in reference to the Trump administration’s abandonment of the deal in 2018.

“So, we thought that coming back in would still be the best outcome, but we’re realistic,” Malley said, acknowledging that Iran’s newly elected government may choose a “different path.” US officials are expressing increasing impatience as Tehran has promised to return to the table in Vienna “soon.”