French President Emmanuel Macron’s arrival in the U.S. kicks off a crucial week for European leaders in an uphill battle to convince Donald Trump to stay in the Iran nuclear deal.

Pressure to win over the U.S. president is growing as a potential make-or-break deadline approaches on May 12, when Trump will decide whether to extend sanctions relief for Iran or risk blowing up the accord.

Macron, German Chancellor Angela Merkel and U.K. Prime Minister Theresa May have spent months coordinating with one another on potential side agreements they hope will convince Trump to remain part of the agreement. They’ve discussed broader foreign policy arguments that could convince Trump it’s in the U.S.’s interest, and personal appeals that could reach the president.

Now comes the test. Macron’s visit Monday and Tuesday - the first formal state visit of the Trump administration - will be quickly followed by Merkel’s working visit to the White House on Friday. While May has no imminent visit planned, she and Trump have been speaking regularly by phone.

“This will be a tag-team effort,” said Barbara Slavin, director of the Future of Iran Initiative at the Atlantic Council, who spent the days ahead of Macron’s U.S. visit in Brussels consulting with European officials about the deal. “It’s very crucial.”

Plan B

In the coming days, representatives from the three European countries hope to finalize written agreements on inspections, missiles and regional aggression that they and U.S. officials can present to Trump as ways of bolstering the protections of the Iran deal without renegotiating it. The European leaders simultaneously are working on a Plan B to maintain the deal without the U.S. But a U.S. withdrawal would greatly increase the chances Iran abandons it.

"We certainly expect this to be a topic that comes up," White House Press Secretary Sarah Huckabee Sanders said Monday on Fox News. "The president’s been very clear about how he feels about this deal, and some changes that he wants to see reflected will certainly come up."

Macron will also make the case to Trump that Europe and the U.S. have the strongest impact when they stick together to combat weapons of mass destruction. The argument could resonate with Trump, who praised a joint strike on Syrian chemical weapons targets by the U.S., U.K. and France earlier this month. The Europeans will also argue that ending the Iran deal could undercut the success in Syria or prolong the U.S. military presence that Trump wants to wind down.

Finally, they will seek to use their personal relationships with Trump to make a more emotional case. In that effort, Macron, seen as one of the world leaders Trump admires and trusts most, will play the leading role. “Macron is their best shot, let’s face it,” Slavin said.

Macron, speaking in an interview with Fox News Sunday, said he wants to keep the accord -- formally known as the Joint Comprehensive Plan of Action, or JCPOA -- intact, and expand it to address Iran’s ballistic missiles.

“Is this agreement perfect and this JCPOA a perfect thing for our relationship with Iran? No,” said Macron. “But for nuclear, what do you have as a better option? I don’t see it. What is the what-if scenario or your plan B? I don’t have any Plan B for nuclear against Iran. So that’s a question we will discuss.”

Macron added that the framework is “better than a sort of North Korean type of situation.”

North Korea Summit

The Syria strikes, the upcoming summit with North Korea and Trump’s recent changes to his national security team are three of the strongest points in Europe’s favor, said Wendy Sherman, a former undersecretary of state under President Barack Obama who led the U.S. negotiating team on the Iran deal.

“He may decide putting all of these factors together that he ought to let his team take a look at all of this to see if there is a better way ahead,” Sherman said. That could provide an opportunity to at least delay a final decision if not a commitment to staying in the deal.

Merkel and Macron also may seek to offer trade assurances in their negotiations, Sherman said. If they put some trade possibilities on the table, “the president may feel that he has moved that ball forward and therefore can create some time and space” on the Iran deal. “Everybody has leverage here, so it’s how that plays out.”

The timing and magnitude of the impending North Korea summit adds considerations for the White House. “Does the president and his national security team really want a crisis at the point that they’re trying to get the North Korea negotiation under way?” Sherman said. “Do they want to deliver a message that America is not a reliable partner?”

No Decision Yet

Two Trump administration officials familiar with the internal deliberations said President Trump has not made a decision yet and that they expect next week’s visits by Macron and Merkel -- as well as ongoing conversations with May and officials from Israel and Saudi Arabia -- to focus significantly on Iran. The remaining weeks before the May 12 deadline are pivotal, said the officials, who spoke on condition of anonymity.

While Trump values the input and alliances with the European leaders, however, the officials each said they don’t expect his thinking to turn on those personal dynamics, or on tangential concerns such as Syria, North Korea or trade. They said the president’s recent public criticism of Iran suggests he may be more convinced than before that the nuclear deal isn’t working.

Alarmed By Missiles

France and Germany are acutely aware of Iranian activities that could contribute to regional instability, but are determined to keep those separate from the nuclear accord. Both governments have expressed alarm at Iran’s ballistic missile program.

Macron aims to present Trump with guarantees on Iran, an official in the French president’s office said. The European countries are working on a separate accord -- probably for the end of this month -- that would allow the western nations that signed the deal to keep Iran in check, the official said.

“The question of the treaty is an important one, but you cannot reduce everything to this treaty,” Merkel said Thursday at a joint press conference with Macron in Berlin, citing Iran’s ballistic rocket program as “a cause for concern.”

Importance of Timing

Europe’s best bet for preserving the deal may be timing.

Trump set his deadline for renegotiating the Iran deal before agreeing to a surprise summit with North Korean leader Kim Jong Un, which is now expected to take place in late May or early June. That sequence could put pressure on the president to delay any action on the Iran deal, according to Mark Fitzpatrick, a former U.S. diplomat who served in South Korea and worked on non-proliferation.

North Korea’s nuclear program is, for any U.S. administration, a far higher risk and priority than Iran’s, said Fitzpatrick, who now heads the U.S. office of the International Institute for Strategic Studies, a think tank. That’s because North Korea’s nuclear weapons and ballistic missiles pose a direct threat to the U.S.

Pulling out of the Iran deal could undermine Trump at the summit, he said. The U.S. routinely accuses North Korea of failing to stand by the nuclear agreements it signed in the past. Withdrawing from the Iran deal just before entering talks with Kim would expose Trump to the same accusation.