Outgoing German Chancellor Angela Merkel’s diplomatic swan song Thursday at the White House was overshadowed by deadly flooding back home and an enduring disagreement with her US hosts over Russia’s Nord Stream 2 pipeline.

Despite the Biden administration’s insistence that this was a “working visit,” Merkel’s one day stay at the White House had the hallmarks of a valedictory farewell for one of Europe’s key political figures.

“I want to take a moment to acknowledge the historic nature of her chancellorship: first woman chancellor in German history, the first chancellor from former East Germany,” President Joe Biden at a joint press conference.

“Chancellor Merkel has been here frequently over the past 16 years. As a matter of fact, she knows the Oval Office as well as I do,” Biden joked, noting that the German leader had now dealt with four US presidents.

Merkel, who will stand down in September, called her host “dear Joe.”

Earlier, meeting with Biden in the Oval, she hailed her “friendship” with the United States and its contribution “to a free and democratic Germany.”

But casting a chill over the encounter was news of catastrophic flooding that has killed at least 59 people in Germany and nine in Belgium, with many more missing.

Merkel called it a day “characterized by fear, by despair, by suffering, and hundreds of thousands of people all of a sudden were faced with catastrophe.”

“My empathy and my heart goes out to all of those who in this catastrophe lost their loved ones, or who are still worrying about the fate of people still missing,” she said.

Biden began his remarks at the press conference by expressing “sincere condolences” over the “tragedy.”

– Russian pipeline headache –

Merkel started with breakfast at Vice President Kamala Harris’ residence. She then headed from the press conference into a White House dinner featuring some big name guests from past administrations that the German leader worked with.

These included two former secretaries of state, Hillary Clinton and Colin Powell, as well as the current man in that position and an architect of Biden’s renewed transatlantic focus — Antony Blinken.

But for all the mutual declarations of admiration, Merkel will leave US shores without the two sides making progress on the vexing question of Russia’s Nord Stream 2 natural gas pipeline.

The huge pipeline is set to funnel Russian natural gas to Germany, Europe’s biggest economy.

Not only will it bypass Ukraine — leading to fears that Russia is deliberately weakening its neighbor’s economy — but the project underscores European energy dependency on an increasingly hostile Moscow.

Despite strong criticism of the pipeline, Biden in May waived key US sanctions on Nord Stream 2 after concluding that it was too late to stop the project and that it was better to seek cooperation with Germany.

Biden acknowledged again that the issue remains unresolved, while insisting that the United States and Germany are on the same page when it comes to threats from Russia.

“While I reiterated my concerns about Nord Stream 2, Chancellor Merkel and I are absolutely united in our conviction that Russia must not be allowed to use energy as a weapon to coerce or threaten its neighbors,” Biden said.

Merkel said that Ukraine, which has already lost swaths of territory to Russian soldiers and Russian-backed insurgents, would not suffer from the Nord Stream 2 bypass.

This is “certainly not a project to replace any kind of transit through Ukraine. Anything else would obviously create a lot of tension,” she said, without specifying what kind of consequences Russia would face if it does use its energy network to squeeze Ukraine.

Biden has invited Ukrainian President Volodymyr Zelensky to the White House later this summer.