President Obama spoke with German Chancellor Angela Merkel on Thursday in his final conversation with a foreign leader as president.

Both leaders agreed maintaining close ties between the U.S. and Europe is “essential to ensuring … a rules-based international order and the defense of values that have done so much to advance human progress in our countries and around the world.”

ADVERTISEMENT

Obama and Merkel forged a strong bond during the president’s eight years in office.

Obama stopped in Germany during his final foreign trip as president and came close to endorsing his German counterpart for another term.

Both leaders' spouses joined Thursday's call.

That partnership is poised to change with Trump taking power.

Trump said in a recent interview Merkel made a “catastrophic mistake” by taking in hundreds of thousands of refugees from Syria and the Middle East, calling it the "straw that broke the camel's back" for the European Union.

Trump has also questioned the value of the NATO alliance.

"I said a long time ago that NATO had problems," Trump told The Times of London. "It was obsolete, because it was designed many, many years ago."

He also reiterated his criticism that allies "aren't paying what they're supposed to pay" for mutual defense.