Iran foments instability in the Middle East but is not behind popular protests in Bahrain and other countries in the region, top US military officer Admiral Mike Mullen said Monday in Qatar.

"Iran, I still believe, is a country that continues to foment instability in the region, take advantage of every opportunity," said Mullen, who is the chairman of the Joint Chiefs of Staff.

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 concerns in this region with Iran and certainly the US has them as well as all the regional players."

Iran "was part of the discussions today with the Saudis," Mullen said.

Mullen, who began Sunday a Gulf tour in Saudi Arabia, could travel to Bahrain, where the US Fifth Fleet is headquartered, as part of his trip, people travelling with him said.

Protests in the tiny Gulf kingdom, which is ruled by a Sunni dynasty but has a Shiite majority, began on February 14, and are still ongoing.

Seven demonstrators have been killed since the anti-regime protests began, according to an AFP tally based on relatives of victims and opposition officials.

However, the US navy has said the demonstrations have not disrupted American operations in the kingdom.

"As far as Fifth Fleet operations, no, the demonstrations have not had any impact here -- we're continuing to conduct our regular business out here," a spokesman for the Fifth Fleet told AFP on Monday.

In the Qatari capital Doha, Mullen met with Crown Prince Sheikh Tamim bin Hamad al-Thani and army chief of staff General Hamad al-Attiyah.

Mullen is to also travel to the United Arab Emirates, Djibouti, possibly Bahrain, and then to Kuwait to participate in ceremonies marking the 20th anniversary of the liberation of the country from Iraqi occupation.