Washington, however, said the entry of foreign troops was "not an invasion".
"This is not an invasion of a country," White House Press Secretary Jay Carney told reporters.
Noting that the US is aware of reports about Saudi forces going to Bahrain, Carney urged all its partners in the region to show restraint and to respect the rights of the people of Bahrain, and to act in a way that supports dialogue instead of undermining it.
"The important factor here is that our overall principles apply to Bahrain and all the countries in the region, which is that we urge restraint," he said.
"We urge nonviolence in response to nonviolent protesters; the respect for the universal rights of people in the region to gather peacefully, to voice their opinions, to have their grievances heard by their governments, and to have greater participation in the political process," Carney said.
"We have long believed and the President has expressed for a long time now that stability in the region will be brought about by dialogue and political reform. It is counterproductive to that goal to in any way repress the expression of those desires that the people of Bahrain, in this case, and other countries, have," he said.
"We are calling on the Saudis, the other members of the GCC countries, as well as the Bahraini government, to show restraint; and that we believe that political dialogue is the way to address the unrest that has occurred in the region, in Bahrain and in other countries, and not to in any way suppress it," he said in response to a question.
US President Barack Obama had said in his speech in Cairo that the unrest in the region is a result of the lack of dialogue and the lack of engagement with the peoples in the region in their governments and in the political process, he said.
"We have called on the Bahraini government to -- as we have others in the region -- to have a dialogue with their people, to listen to their grievances, to adopt political reforms, to respect the universal rights of their people.
I think, broadly speaking, in the countries of the region, the leaders in the region will be judged by how they deal with this process. We think it's important for the future of the region, for the peoples in these countries, that their voices be heard and their legitimate aspirations be addressed," Carney said.