by Peter Baker and Julie Hirschfeld Davis

WASHINGTON — President Donald Trump will come under increasing pressure from visiting French and German leaders this week not to scrap the three-year-old nuclear agreement with Iran next month as U.S. and European negotiators make tentative progress toward a new deal to toughen the limits on Tehran.

President Emmanuel Macron of France arrived Monday at the White House for the first state visit of Trump’s presidency, intent on using his unusual bond with the U.S. president to try to persuade him to preserve the Iran deal, at least for now. While not as close personally to Trump, Chancellor Angela Merkel of Germany will follow Friday to reinforce the message.

The back-to-back visits come weeks before a May 12 deadline set by Trump to “fix” the Iran agreement or walk away from it. Under the agreement, sealed in 2015 by President Barack Obama, Iran has curbed its nuclear program in exchange for relief from crippling international sanctions. But Trump and other critics have assailed it because it begins to expire after a decade and does not block Iran’s missile development or try to stop it from destabilizing the region.

In recent weeks, U.S. and European negotiators have made progress toward side agreements that would lay out new standards for Iran to meet or risk the reimposition of sanctions by the West. Negotiators have generally reached a consensus on measures to constrain Iran’s ballistic missile program, according to people briefed on the talks, but remain divided over how to extend the restrictions of the original agreement due to lapse starting in 2025.

Most importantly, the Europeans want assurances that if side agreements are reached, the United States will stay in the deal, a hard commitment for U.S. officials to make given Trump’s mercurial nature. But European leaders hope they can persuade him to hold off by showing enough progress in negotiations that he can claim he is making the deal better.

“I suspect that this will be a very difficult conversation,” said Wendy R. Sherman, the former top State Department official who negotiated the Iran deal for Obama. “I’m sure that Macron will say how important staying in the deal is to a strong trans-Atlantic relationship in all things, particularly security. I think Merkel will deliver the same message on Friday.”

Even so, the White House signaled Monday that Trump enters the talks with one set impression. “He thinks it’s a bad deal — that certainly has not changed,” said Sarah Huckabee Sanders, the White House press secretary.

The fate of the Iran agreement could influence the president’s forthcoming meeting with Kim Jong Un, the North Korean leader who already has a small nuclear arsenal. Whatever its flaws, U.S. officials understand that canceling the Iran deal days or weeks before that meeting might complicate Trump’s chances of making an agreement with Kim.

Mohammad Javad Zarif, Iran’s foreign minister, implicitly made that point Monday by noting that the negotiations that led to the nuclear agreement between his country and six world powers involved give and take by all sides.

“And now the United States is saying, ‘What’s mine is mine and what’s yours is negotiable. But whatever I gave you, now I want it back,'” Zarif said in an interview with The National Interest, a Washington policy magazine. “Who would, in their right mind, deal with the U.S. anymore?”

Trump faces conflicting positions among his own advisers as he reconstitutes his national security team. John R. Bolton, his new national security adviser, has long advocated simply ending the Iran deal, while Mike Pompeo, set to become secretary of state, is open to keeping it if strong new provisions can be negotiated.

Macron arrived in Washington to a festive welcome. American and French flags flew on Pennsylvania Avenue as he and his wife, Brigitte Macron, were greeted at the White House by Trump and the first lady, Melania Trump.

Macron reached in for a hug and kissed Donald Trump on both cheeks, French-style, a sign of their warm ties. The two couples headed inside for a few minutes and then out to the South Lawn, smiling and chatting casually as cameras recorded the moment.

Wielding shovels, the two presidents moved some dirt around where a tree was to be planted, a gift from the Macrons. The tree, a European sessile oak, came from Belleau Wood, where, during World War I, nearly 10,000 U.S. Marines were killed or injured in battle in June 1918. From there, the two couples flew by helicopter to George Washington’s Mount Vernon estate for dinner.