DARWIN, AUSTRALIA -- President Obama closed out a quick trip to Australia with a visit to the Northern Territory, scene of deadly fighting during World War II and now home to a fast-expanding military base aimed partly at keeping tabs on an assertive China.
Obama didn't mention China in brief remarks Thursday at an air force base in this coastal city. But he made the case that the new defense pact between the U.S. and Australia is vital to protecting commercial traffic in the Pacific.
Speaking to nearly 1,700 Australian troops and a few dozen Marines, Obama laid out a reason why "we're deepening our alliance here."
“This region," he said, "has some of the busiest sea lanes in the world, which are critical to all our economies."
That seemed a reference to a simmering dispute in East Asia involving a major commercial hub -- the South China Sea. China is asserting broad jurisdiction over the South China Sea, upsetting smaller East Asian nations that also claim sovereignty.
By deploying more warplanes and 2,500 Marines to northern Australia in the coming years, the U.S. is signaling that it will contest any Chinese push for military dominance in the region.
Bejing is wary of the move. Chinese Foreign Ministry spokesman Liu Weiminon, speaking to reporters Wednesday, questioned whether strengthening military alliances is the best idea in a period of global economic unrest.
Presenting himself as a solid ally and friend in the Pacific, Obama tried to endear himself to the Australians in his short stay. He took a stab at an Australian accent and greeted crowds with a breezy "G'day."
Visiting a local high school in Canberra on Thursday, he fielded a question from one student about teen heartthrob Justin Bieber. Should Obama partner with Bieber as a way to reach more students? she asked.
Obama called Bieber a "very nice young man" but maintained that "hanging around with Justin Bieber" is no substitute for "the ideas I put forward."
In his appearance here, Obama led the soldiers in a chant of "Aussie, Aussie, Aussie!" and told them he had gotten "the most unique gift I've ever received as president -– crocodile insurance."
Over and over he thanked Australia for its military sacrifices. Shortly before leaving the country he visited a memorial to the Peary, a U.S. destroyer that was sunk during a Japanese air raid in 1942. He and his Australian counterpart, Prime Minister Julia Gillard, pinned cards to a pair of wreaths overlooking Darwin Harbor, next to a 4-inch gun that was salvaged from the wreck.
Afterward, Obama chatted with a few elderly survivors of the air raid, hugging one woman who broke down in tears.
Obama had twice planned to visit Australia, only to cancel because of pressing business back home. Still, he got a largely warm reception over the last two days. People in the crowds gathered along the motorcade route in Darwin wore tricorn hats fashioned out of newspaper, with the bill reading: "Obama Territory."
A few protesters held up signs objecting to an increased U.S. military presence. "Darwin Residents Against War!" read one sign.
Next up for Obama is a series of summit meetings in Indonesia. He arrived in Bali on Thursday night and will spend the next two days talking to leaders of East Asian nations and the states belonging to ASEAN –- the Assn. of Southeast Asian Nations.
Chinese Premier Wen Jiabao will attend, and U.S. officials anticipate a fierce debate over the South China Sea.
-- Peter Nicholas