WASHINGTON – State Department officials are seeking a commitment from their European counterparts that they will work to “improve” the Iran nuclear deal over an undetermined period of time – a request short of the concrete and swift policy changes demanded of them by US President Donald Trump last month.According to a diplomatic cable seen by Reuters, US officials are asking the governments of Britain, France and Germany to commit to “work together to seek a supplemental or follow-on agreement” to the 2015 international deal governing Iran’s nuclear program “that addresses Iran’s development or testing long-range missiles, ensures strong [International Atomic Energy Agency] inspections, and fixes the flaws of the ‘sunset clause.’”It is a departure from the president’s initial request of the “E3” powers. In January, Trump announced that he was waiving nuclear-related sanctions on Iran for the “last time,” and that he would allow them to enter back into effect in 120 days if Europe fails to adopt a dramatically new posture on the nuclear agreement.“This is a last chance,” Trump warned.“In the absence of such an agreement, the United States will not again waive sanctions in order to stay in the Iran nuclear deal. And if at any time I judge that such an agreement is not within reach, I will withdraw from the deal immediately.”The Trump administration believes that the nuclear deal – which was meant to shut down all of Iran’s paths to a nuclear weapon – has several critical flaws.It believes that Tehran’s intercontinental ballistic missiles, which are designed to carry nuclear payloads, are inseparable from its nuclear program and should have been addressed in the accord – pointing to North Korea’s missile threats as precedent; It believes that Tehran can deny or stall international inspectors from accessing its military sites, where US intelligence suspects that Iran has conducted nuclear weapons experimentation in the past and may prove a black hole in the future; And it believes that the expiration of several key provisions in the agreement provide Iran with a legitimate pathway to a nuclear weapons capability, allowing them to grow the size and efficiency of the program to an industrial scale.European powers have long disagreed with these points. But faced with an American president seriously threatening to withdraw from the accord, EU diplomats are quietly engaging their US counterparts to figure out what it will take to keep the deal intact.REACHING A full-blown supplemental deal by May 12 – the 120-day deadline set by Trump last month – is seen as an impossibility by some US and European officials even if there was agreement on the underlying issues, which there is not.In an interview last week, a senior State Department official described the effort with the Europeans as a two-phase process.During the first, from January 12 to May 12, the US will seek to get the Europeans to agree on the weaknesses that need to be fixed, he said.“We want a commitment from them that these are the deficiencies that need to be addressed... and an agreement that we will seek an agreement. That’s it,” the official said.The second phase, to begin immediately after May 12, would take that understanding to the other parties to the deal – Iran, Russia and China – to see if there was some way to address these issues.The official said there were three possible avenues to do this: amend the existing pact, negotiate a supplemental agreement, or seek a new UN Security Council resolution to make the changes.But the White House has already ruled out the possibility of negotiating with Iran directly in the short term. They instead seek to circumvent Tehran entirely and create a multilateral addendum agreement that imposes new terms onto the nuclear deal.Europe fears this approach would lead the Iranians to walk away from the agreement outright, and have thus far refused to go along. Now the White House is simply asking them to agree publicly to work towards a new agreement.The senior US official said that if Washington were to pursue a supplemental accord – which is common in arms control – it would want the support of Iran, Russia and China, but could live with just the agreement of Germany, France and Britain.But given Trump’s gutting of the State Department and his public flagellation of his secretary there, Rex Tillerson, European diplomats are unclear as to who is speaking for the administration, or of what will truly satisfy the temperamental president.“Has the Trump administration shifted its stance? We don’t know,” said a senior European diplomat on Friday.Another said: “The reality is that what we are doing now is to try to get the best package possible to convince Trump.”“Nobody knows what Trump will do or wants,” he added.Reuters contributed to this report.