CANBERRA, Australia—The Australian government has asserted its right to fly military patrols over contested South China Sea islands claimed by Beijing, but said on Sunday it hadn’t had formal talks with the U.S. on naval missions as a direct challenge to Chinese muscle-flexing.

Defense Minister Kevin Andrews, in an interview with The Wall Street Journal from Singapore, said Canberra had sent long-range maritime patrol aircraft over the South China Sea and Indian Ocean, and would continue to do so despite the potential for obstruction from China.

“We’ve been doing it for decades, we’re doing it currently…and we’ll continue to do it into the future,” Mr. Andrews said, in one of his first foreign press interviews since taking the post after a shake-up in Prime Minister Tony Abbott’s conservative government last year.

“We don’t see there’ll be any change to that operation. It’s been a long-term operation and it’s been well known by all the countries in the region,” Mr. Andrews said.

Top U.S. Navy and Marine commanders in the Pacific have been urging close ally Australia since last year to consider joining multilateral naval policing missions in the South China Sea, potentially alongside Washington’s chief regional ally Japan, helping to reinforce the rebalance of U.S. forces to the Asia region.