Stoltenberg's office requested a meeting with Obama well in advance of the visit, but never heard anything from the White House, two sources close to the NATO chief told me.
The leaders of almost all the other 28 NATO member countries have made time for Stoltenberg since he took over the world's largest military alliance in October. Stoltenberg, twice the prime minister of Norway, met Monday with Canadian Prime Minister Stephen Harper in Ottawa to discuss the threat of the Islamic State and the crisis in Ukraine, two issues near the top of Obama's agenda.
Kurt Volker, who served as the U.S. permanent representative to NATO under both President George W. Bush and Obama, said the president broke a long tradition. "The Bush administration held a firm line that if the NATO secretary general came to town, he would be seen by the president ... so as not to diminish his stature or authority," he told me.