A tree that the presidents of the U.S. and France planted together as a symbol of friendship has died — just as the relationship between the two leaders shows signs of withering. Last year, when French President Emmanuel Macron visited the White House, he presented President Trump with a gift of an oak tree sapling from the site of a World War I battle in France. Together, they planted it in a ceremony on the South Lawn of the White House.

After the presidents, along with their wives, planted the tree, they departed for a tour and dinner at Mount Vernon, President George Washington's residence in Virginia. Then, the tree disappeared.

President Donald Trump and first lady Melania Trump participate in a tree planting ceremony with French President Emmanuel Macron and his wife, Brigitte Macron, on the South Lawn of the White House in Washington, D.C., on April 23, 2018. Jim Watson / AFP/Getty Images

After some confusion, an official from Macron's office set the record straight. The tree was put in quarantine as a safety measure, like other foreign plants or animals brought into U.S. territory. The official said Mr. Trump insisted on holding a symbolic planting ceremony despite the quarantine requirement.

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But more than a year later, the tree has not come out of quarantine — because, as it turns out, it died there, the Agence France-Presse (AFP) news agency reports. In keeping with that symbolism, the presidents' relationship with one another has also taken a turn for the worse since then.

Just months after Macron's state visit and the tree planting, President Trump unleashed an angry Twitter jab at the French president. Mr. Trump had just arrived in France for the 100th anniversary of the end of World War I when he tweeted that Macron made an "insulting" proposal to build up Europe's military to counter the U.S., China and Russia.

The two leaders worked to ease tensions after the diatribe, which threatened to divert attention away from the WWI commemoration. Ironically, their "friendship tree" came from Belleau Wood, a northern French forest where 2,000 American Marines died in battle in 1918.

Ahead of Mr. Trump's recent trip to France for the D-Day anniversary, some tensions remained between the two men. They disagree on several important issues, such as Iran, world trade and climate change, the Associated Press reports. However, despite their differences, they held a two-hour bilateral meeting which a top official at Macron's office called "positive."

Together, the two presidents stood side by side at ceremonies commemorating the 75th anniversary of D-Day — but back in the U.S., their "friendship tree" didn't make it to its first birthday.