Obama heads to Europe amid British referendum's aftershocks

WASHINGTON -- President Barack Obama embarked Thursday on a five-day, two-country mission to buck up a beleaguered Europe and brush back an aggressive Moscow on what is expected to be his last presidential visit to the continent.

Obama departed mid- morning on his way to a summit of NATO allies in Warsaw before moving on to Seville and Madrid for his first presidential visit to Spain. In both corners of the continent, he'll be surrounded by leaders still reeling from Britain's decision to pull out of the European Union and sorting through uncertainty about the future of the decades-old experiment in international cooperation.

The White House said Obama will arrive with words of reassurance the departure -- whenever it occurs -- won't disrupt the decades-old trans-Atlantic ties that bind.

He'll emphasize Britain's exit, which does not affect its membership in NATO, only makes the 28-member military alliance more essential and its cooperation with the European Union more important.

And amid leaders' anxiety about whether his possible successor, Republican Donald Trump, would retrench from Europe, Obama will make the case for stronger alliances and the benefits of globalization.

"He feels like all leaders in Europe and in the United States -- including himself -- have a responsibility in the face of all these challenges to the trans-Atlantic order that we've built to make the case on behalf of the values that the United States and Europe have stood for and the benefits to our countries," said Ben Rhodes, Obama's deputy national security adviser.

The president's arrival early today will be his first chance to deliver that message in person.

Obama's agenda goes beyond the so-called Brexit fallout. NATO plans to tout new efforts to send signals to Russia. The alliance recently agreed to bolster its presence in the east by deploying four multinational battalions on a rotational basis to Estonia, Latvia, Lithuania and Poland.

Obama also will meet Saturday with Ukraine's President Petro Poroshenko to discuss the status of the stalled 2015 Minsk peace deal, which was intended to ease tensions after Russia's incursion into eastern Ukraine. NATO leaders also will discuss the rising threat of Islamic State attacks in Europe, the effort to address the migrant crisis caused by violence in the Middle East and North Africa and continued commitments to the mission in Afghanistan.