The U.S. and three European allies have threatened Iran with another resolution at the U.N. nuclear watchdog’s board demanding action on issues such as explaining uranium traces found at undeclared sites, but left open whether or when they might follow through. The warning delivered by Britain, France and Germany – the so-called E3 – and the U.S. to a quarterly International Atomic Energy Agency Board of Governors meeting published on Thursday comes as the West’s standoff with Iran has been complicated by secret U.S.-Iran talks. A November resolution ordered Tehran to cooperate urgently with the IAEA’s investigation into the presence of uranium particles at three undeclared sites, since narrowed down to two. Western powers have recently condemned Iran for stonewalling the IAEA on that and other issues like the re-installation surveillance cameras removed last year, and for enriching uranium to up to 60% purity, close to weapons grade. But in parallel diplomats say the United States has held secret “de-escalation” talks with Iran, potentially muddying the waters. Those de-escalation talks, which Washington does not acknowledge, cover issues such as Iran’s recent slowdown of enrichment to 60% purity, frozen Iranian funds abroad, and a prisoner swap, diplomats say. “If Iran fails to implement the essential and urgent actions contained in the November 2022 Resolution and the 4th March Joint Statement in full, the Board will have to be prepared to take further action in support of the (IAEA) Secretariat to hold Iran accountable in the future, including the possibility of a resolution,” the four Western powers said in a statement to the 35-nation IAEA board.