The big question is whether other countries are ready to join with Washington. So far, Europe is favoring diplomacy instead. Iran is poised to surpass a key uranium stockpile threshold, threatening an accord it reached in 2015 with world powers aimed at curbing its nuclear activity. Tehran made no immediate announcement Thursday that it had done so, perhaps waiting to hear what Europe can offer at a meeting Friday to keep the deal alive.
French President Emmanuel Macron is trying to dial back tensions, saying he hopes to convince Trump to open talks with Iran and avoid a war that would engulf the Middle East. The two men are to meet Friday at a Group of 20 summit in Japan.
"There is no brief war," Macron warned. "We know when it's starting, but not when it's finishing." Special Representative for Iran Brian Hook met with top European diplomats Thursday in Paris, and he told The Associated Press that he wants to get tougher on Iran, instead of clinging to the nuclear deal that the U.S. pulled out of last year.
War with Iran is "not necessary," Hook said in an interview. "We are not looking for any conflict in the region," he said. But if the U.S. is attacked, "we will respond with military force." To that end, the U.S. is trying to drum up support for an international naval force in Persian Gulf, notably to protect shipping.
"The president would like to see an international response of like-minded countries who could come together and contribute assets that could be used to enhance maritime security in the region," Hook said.
But acting U.S. Defense Secretary Mark Esper, at his first NATO meeting this week, left Brussels with no firm commitments after discussing the idea with U.S. allies. Tensions have been rising in the Middle East after the U.S. imposed new sanctions on Iran to cripple its economy. Citing unspecified Iranian threats, the U.S. has sent an aircraft carrier to the region and deployed additional troops alongside the tens of thousands already there.
The U.S. has been worried about international shipping through the Strait of Hormuz since tankers were damaged in May and June in what Washington has blamed on limpet mines from Iran, although Tehran denies any involvement. Last week, Iran shot down a U.S. Navy surveillance drone, saying it violated its territory; Washington said it was in international airspace.
Iran recently quadrupled its production of low-enriched uranium as it slowly steps away from the nuclear deal. Even though Trump pulled the U.S. out of it, Britain, France, Germany, Russia and China are still part of the pact.
Iran previously said it would surpass a 300-kilogram stockpile limit set by the accord by Thursday. Tehran made no statements about it, possibly because it was a holiday weekend in the country, but also because it could be waiting for the outcome of a key meeting Friday in Vienna by European officials on the nuclear deal.
An Iranian official in Vienna said the country was 2.8 kilograms below that limit Wednesday, and there will be no new assessment until "after the weekend." Even if it surpasses that limit, "we are not breaching the deal," said the official, who spoke on condition of anonymity because of the sensitivity of the discussions involving the deal.
The official insisted Iran wants to "save the deal" and urged Europeans to start buying Iranian oil or give Iran a credit line to keep the accord alive. At the United Nations, Majid Takht Ravanchi, Iran's ambassador to the U.N., told reporters that if his country exceeded the limit, it could be quickly reversed as soon as Tehran sees recovery in its oil and banking sectors, he said, adding that he hopes "tangible results can be achieved" in Vienna "so that we can reverse our decision."
Hook wouldn't comment on whether Iran had surpassed the limit, but he estimated that Iran is still at least a year away from building a nuclear weapon. Iran denies that it seeks nuclear weapons. "That is the standard of the Iran nuclear deal, that Iran should never be able to get to a nuclear weapon in less than a year. This is relevant because Iran still is they still hold the title of the world's leading state sponsor of terrorism," he said.
Iranian Foreign Minister Mohammad Javad Zarif sent a letter urging European signatories to the accord to implement their commitments, saying that Iran's next steps depend on that, Iranian state TV reported Thursday.
Britain, France and Germany are finalizing a complicated barter-type system known as INSTEX to maintain trade with Iran and avoid U.S. sanctions, as part of efforts to keep the nuclear deal afloat. Hook dismissed those efforts, suggesting that no companies will use such a system because they'd rather trade with the U.S. than Iran.
Instead, he said, "We would like to see the European Union impose sanctions on those people and organizations that are facilitating Iran's missile program. ... If you don't do sanctions, it also sends a signal of sort of tacit approval."
He suggested frustration that France has not been more outspoken about Iran recently but played down any "trans-Atlantic rift." France is among those seeking to play a mediating role. Macron sent his diplomatic adviser to Tehran last week and spoke to Iranian President Hassan Rouhani this week.
Many in Europe are relieved that Trump did not order military retaliation against Iran last week for the drone shootdown, but they are rattled that he was close to doing so. It is not clear whether the Trump administration discussed the operation with any European allies ahead of time.
The U.S. announced additional sanctions Monday on Iranian leaders over the drone attack. Iran's Zarif criticized Trump on Thursday, tweeting that "sanctions aren't (an) alternative to war; they ARE war."
The U.S. has said it may also sanction Zarif, who helped negotiate the 2015 nuclear deal.
Associated Press writers Philipp Jenne in Vienna, Edith M. Lederer at the United Nations and Jon Gambrell in Dubai, United Arab Emirates, contributed.