“We have to be prepared in the event that these demonstrations get out of control,” Panetta told Foreign Policy magazine.
He did not offer any specifics.
But the Pentagon, responding to a wave of anti-American protests sweeping the Middle East, has planned to bolster security at the U.S. Embassy in Khartoum, Sudan, following similar reinforcements sent to Libya and Yemen, a U.S. official said.
President Barack Obama on Saturday rejected any denigration of Islam but said there is no excuse for attacks on U.S. embassies, insisting he will never tolerate efforts to harm Americans.
“I have made it clear that the United States has a profound respect for people of all faiths,” Obama said in his weekly radio address. “Yet there is never any justification for violence .... There is no excuse for attacks on our embassies and consulates.”
However, Obama repeated a vow to bring the attackers of the U.S. consulate in Libya to justice. “We will not waver in their pursuit,” he said.
The president also said the turmoil should not deter U.S. efforts to support democracy in the region or elsewhere.
“Let us never forget that for every angry mob, there are millions who yearn for the freedom, and dignity, and hope that our flag represents,” he said.
The deployment in Sudan follows the roughly 100 Marines that already have landed in Libya and Yemen as fury over a film that insults the Prophet Mohammed tore across the region.
Furious protesters targeted symbols of U.S. influence in cities across the Muslim world, attacking embassies,
Police in Sydney fired pepper spray to contain protesters trying to enter the building housing the U.S. consulate on Saturday, as Australia became the latest focus of disturbances.
Bottles, shoes and other objects were hurled during the clashes with police, which resulted in eight arrests, with six police officers injured as the unexpected protest brought parts of the city to a standstill.
Shoppers looked on in surprise as protesters, including children, shouted “Down, down U.S.A.” and waved banners such as “Behead all those who insult the prophet”.
Hundreds also demonstrated in Indonesia and the Maldives.
At least six protesters died in Egypt, Tunisia, Lebanon and Sudan on Friday as local police battled to defend American missions from mobs of stone-throwers.
The protests broke out when Muslims emerged from mosques following weekly
U.S. ambassador Chris Stevens and the three other Americans died Tuesday when a mob torched the American consulate in Benghazi, Libya.
Panetta argued it was too early to say what exactly happened in Benghazi and who was to blame for the attacks.
“It’s something that’s under assessment and under investigation, to determine just exactly what happened here,” he said.
But the defense secretary cautioned that even though the United States had dealt the al-Qaeda terror network a heavy blow in recent years, there were other extremists ready to pick up the torch.
“We always knew that we would have to continue to confront elements of extremism elsewhere as well,” he insisted.
“They’re going to resort to these kinds of tactics, because in many ways I think they have lost their voice in the Middle East,” Panetta added.