The U.S. ambassador to the United Nations on Thursday urged European nations that support the nuclear deal with Iran to put in writing their ideas to extend the expiring arms embargo on the Islamic Republic, indicating that the Trump administration may be willing to compromise on its demand for an indefinite extension.

Kelly Craft said in an interview with The Associated Press that the United States is “keeping the space open” for talks with the United Kingdom, France and Germany, as well as Russia and China. The five veto-wielding members of the U.N. Security Council still support the 2015 nuclear agreement with Iran which U.S. President Donald Trump pulled out of in 2018.

The Trump administration has said repeatedly it will not allow the arms embargo provision in the Security Council resolution endorsing the nuclear deal to expire as required on Oct. 18 — a commitment reiterated by Craft.

The U.S. initially circulated a resolution to the 15-member council to indefinitely extend the arms embargo which was seven pages long and had 35 paragraphs. This week, following discussions with council members, it circulated a revised draft with just four paragraphs calling for an indefinite extension, and on Thursday the U.S. put the resolution in a form that could be put to a vote.

But Craft said that before any vote “I want to exhaust all of the space that I have available, and hopefully receive something in writing from the E3” — the three European countries, Britain, France and Germany.

She stressed that she must have something in writing to give to Trump and U.S. Secretary of State Mike Pompeo.

Asked about reports the Europeans have talked about a six-month extension of the arms embargo, she replied: “They mentioned six months. They mentioned a one-year (extension). They mentioned other elements. They’ve mentioned a code of conduct, and I haven’t seen anything in writing.”

“My puzzling question is, why on earth would the E3 hold up international peace and security? Why would they not come forth with all of their talking points to everyone? Why wouldn’t they put that in writing and allow me to take this to the secretary and to the president?” Craft asked.

She said the Europeans “understand more than anyone” the importance of extending the arms embargo against Iran, which she called “the number one state sponsor of terrorism.”

Craft said she has been having meetings with the E3 for the last three week, and has also been meeting for the last two weeks with Russia and having phone conversations with China, as well as other members of the 15-nation Security Council.

The foreign ministers of Russia and China, in separate letters to U.N. Secretary-General Antonio Guterres and the Security Council last month, were sharply critical of the U.S. effort to indefinitely extend the arms embargo. They gave every indication they would veto any such resolution if it got the minimum nine “yes” votes in the 15-member council, which appears unlikely.

Both Russia’s Sergey Lavrov and China’s Wang Yi said Trump withdrew from the 2015 nuclear agreement and now has no legal right to try to use the U.N. resolution endorsing the deal to indefinitely continue the embargo.

If the resolution is defeated, Pompeo suggested the U.S. would invoke the “snap back” mechanism in the 2015 nuclear deal that would restore all U.N. sanctions on Iran. “Snap back” was envisioned in the event Iran was proven to be in violation of the accord, under which it received billions of dollars in sanctions relief in exchange for curbs on its nuclear program.

“Obviously we will use the most important tool, whatever it is, whether it’s `snap back', whether it is hopefully just going into the council and extending this renewal, we will not take no for an answer,” Craft said.

She said the U.S. has circulated to council members a six-page memo from U.S. State Department legal advisers outlining why the United States remains part of the 2015 Security Council resolution and still has the right to use the `snap back' provision.

Craft said council members face a choice between “sponsoring terrorism” or promoting international peace and security.

“We have a moral responsibility to make certain that this murderous regime does not have access any longer to exporting and to arming its proxies,” Craft said. “I know the biggest threat to international peace and security is Iran, and I’m going to do everything in my power because every day is a life, and we cannot forget that lives are at risk here and we owe it to the Iranian people for their future to change the behavior of this regime.”

She said the E3’s “best option” is to engage on the U.S. draft resolution, put something in writing and resolve differences in the Security Council.

“And if they think for one second that `snap back' is hollow they need to think twice,” Craft said.