Munich: US Secretary of State John Kerry flew into Munich on Saturday and met with Oman’s ailing Sultan Qaboos.

State Department spokeswoman Jen Psaki said the purpose of the private meeting was “to express his gratitude for their longstanding and strong relationship.”

The sultan has not returned to Oman since traveling overseas for medical tests six months ago.

Kerry was only accompanied by one aide for the private talks, with the small number of reporters traveling with the top US diplomat en route for India barred from access or from photographing the event.

Qaboos, 74, traveled to Germany in July for medical tests. Since then, he has made only one appearance, in a brief video that was broadcast on national television on Nov. 5.

In it, Qaboos spoke of what he called the “good results” of his treatment, but added that his condition requires monitoring.

Kerry last met with the sultan in May 2013 during an official trip to Muscat.