President Donald Trump warned Iran not to restart its nuclear program as French President Emmanuel Macron urged him to remain in the international agreement curbing the Islamic Republic’s atomic efforts.

Trump made his differences with Macron clear from the outset of a state visit on Tuesday, beginning an Oval Office meeting by saying the Iran deal was “insane, ridiculous, should never have been made.”

The U.S. president also warned Iran not to resume its nuclear program, even if the international accord collapses and U.S. sanctions resume. “If they restart their nuclear program, they’re going to have bigger problems than ever before,” Trump said.

Trump plans to announce by a May 12 deadline whether or not the U.S. will remain in the multi-nation Iran nuclear deal reached in 2015. If the U.S. withdraws, Iran could accelerate its nuclear program or consider actions such as leaving the nuclear Non-Proliferation Treaty. European leaders including Macron are seeking to convince Trump the world is safer with the deal than without it.

No European leader has a better relationship with the president, and Macron hopes to tap that goodwill to persuade Trump not to abandon an international agreement to curb Iran’s nuclear program. He wasn’t able to keep the U.S. president from backing out of the Paris climate accord, but has nonetheless urged Trump to stick to American commitments to reduce carbon pollution.

Side Agreements

Macron urged the president to consider the nuclear deal “in a wider regional context,” including the situation in Syria, where the U.S., France and the U.K. recently launched a joint strike to retaliate against the regime’s use of chemical weapons on rebels.

“We have a common objective,” Macron said. “We want to make sure there’s no escalation and no nuclear proliferation in the region. We now need to find the right path forward.”

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.

The state visit officially began Tuesday morning, with a ceremony on the South Lawn of the White House featuring 500 members of the U.S. Armed Forces. Cabinet secretaries, members of Congress, military families and students from a French immersion school in Maryland were invited to attend.

Macron used the occasion to urge Trump to maintain past U.S. commitments to joint action with allies.

“It is together that we can resist the rise of aggressive nationalisms that deny our history and divide the world,” Macron said in French, according to a translation. “It is together that we will build a new, strong multilateralism that defends pluralism and democracy in the face of ill winds.”

“We do not always agree on the solutions,” Macron said of climate change. “But it is also where the fate of our children is at stake.”

‘Enduring Friendship’

Trump welcomed Macron by celebrating “the wonderful friendship we have developed over the past year” which he said “is a testament to the enduring friendship” between the U.S. and France.

He predicted that Macron “is going to be a great president of France.”

Trump is delivering Macron the most lavish welcome for a foreign leader of his presidency so far, including his first state dinner. The fanfare is intended to rival Trump’s reception in France last year, where he attended Bastille Day celebrations and was feted with a military parade along the Champs-Élysées and dinner at the Eiffel Tower.

On Monday evening, Trump, Macron and their wives toured Washington’s monuments in the Marine One helicopter and landed at Mount Vernon, the home of George Washington, for a dinner.

The two leaders will hold a series of meetings Tuesday morning and a news conference ahead of dinner at the White House.

The state dinner Tuesday night will feature American food with French influences, including goat cheese gateau, rack of spring lamb, Carolina Gold rice jambalaya, and a nectarine tart and creme fraiche ice cream.