She said the initial six-month rotation of Fox Company will not include heavy equipment, vehicles or aircraft. Air and sea movements in support of this rotation will be minimal, she said.
"There are no U.S. military bases in Australia, and this will not change," she said.
Defense Minister Stephen Smith told the Marines on Wednesday at an Australian army barracks outside Darwin where they will be based that their arrival was a historic day in the 61-year-old alliance between Australia and the United States.
He rejected analysis that the closer military ties between Australia and the United States, Australia's most important security ally, are a response to the growing military assertiveness of China, Australia's most important trading partner.
"We don't see China or India as a threat," he said. "There is nothing inconsistent with our relationship with China and our long-standing, successful alliance with the United States."
U.S. Ambassador to Australia Jeffrey Bleich told the welcoming ceremony that the Asia-Pacific region was the "most dynamic area in the world."
"This is the fastest growing economic area and also the one that is enduring the greatest demographic change and we want to make sure that it continues to be a peaceful, prosperous and stable area," he said.
"The way that we accomplish that is by ensuring that trade routes are open and that we're prepared for any issue that could come up," he added.