Iran continues to foment instability in the Middle East but is not behind popular protests in Bahrain and other countries in the region, Mullen said Monday in the Qatar.

“Iran, I still believe, is a country that continues to foment instability in the region, take advantage of every opportunity,” said Mullen.

But “from my perspective that has not been the principal focus of what happened in Egypt or what happened in Bahrain or any of these other countries,” he said, referring to popular protests against various Middle East regimes.

“Those are by and large internal issues, as opposed to issues fomented by some external forces,” Mullen said, although “there’s always concern in this region with Iran, and certainly the US has them as well as all the regional players.”

He began his visit in Saudi Arabia this weekend and told reporters before leaving Washington, that he would visit countries with leaders “who have been good friends for a long time.”

Iran also “was part of the discussions with the Saudis,” Mullen told reporters.

Mullen traveled to Qatar on Monday, and will then travel on to the United Arab Emirates, Kuwait and Djibouti.

In Kuwait, he plans to participate in a celebration in Kuwait marking the 50th anniversary of the country's independence from the United Kingdom and the end of the 1991 Gulf War.

The chairman also plans to stop in Djibouti, where demonstrators inspired by revolts that toppled leaders in Egypt and Tunisia have clashed with riot police.

Mullen's itinerary did not initially include Bahrain, a cornerstone of US military power in the Gulf and the site of deadly clashes between anti-government protesters and security forces last week.

Now, however, people travelling with him said Mullen could travel to Bahrain, where the US Fifth Fleet is headquartered.

Gates’ tour through the Gulf region was planned last December, but has taken on fresh relevance in light of regional upheaval. 

I think the dominant issue of the day is going to be stability in the Middle East,” Mullen said. “And so part of what I hope to accomplish is just reassure our friends, and also just listen to what's on their mind.”

Mullen said that the spread and speed of the democracy demonstrations — the reign of Egypt's 30-year ruler, Hosni Mubarak, for example, was toppled in 18 days — was “stunning.”

“It’s stunning to me that it’s moved so quickly,” Mullen told reporters aboard his aircraft shortly before landing. “We've talked about the underlying issues for a long time, but it’s the speed with which this is happening. ... Everybody's working hard to get ahead of it.”

Last week, Mullen visited Israel and Jordan to reassure them of the US partnership.

Upon returning from that trip, Mullen took the Defense budget to the House and Senate Armed Services committees, where he cautioned lawmakers against cutting aid too quickly to countries where protest movements are rapidly unfolding.