US Defense Secretary Lloyd Austin has been rebuffed three times in attempted calls to Chinese counterparts, according to a Financial Times report that has not been denied.

China's government-allied Global Times newspaper reported that while China is open to bilateral military discussions, Austin had tried to connect with Xu Qiliang, the powerful vice chairman of the Central Military Commission, the Chinese Communist Party organ which oversees the military, rather than just with the country's Minister of Defense, Wei Fenghe.

Austin's approach of trying to see Xu, who is close to President Xi Jinping, was "an unprofessional and unfriendly act of disregarding diplomatic protocol and international common practice," wrote the Global Times, which often echos official views.

Pentagon spokesman John Kirby confirmed that Austin has not connected with China's top military officials.

"We certainly desire to have a dialogue with our counterparts in Beijing, and we're still working our way through exactly what that's going to look like and how that's going to transpire," he said Tuesday.

The Pentagon has been open about the desire to have top-level bilateral discussions with China amid a rise in tensions between the two sides.

Washington has kept up a strong military presence in the region, especially with naval deployments, to make clear its rejection of Beijing's claim on disputed territories in the South China Sea, its threat to retake US ally Taiwan by force, and its expanded military presence beyond East Asia.

China meanwhile sees the regular passage of US ships through the South China Sea and the Taiwan Straits as threats to its sovereignty, and its dealings with Taiwan as a strictly domestic issue.

China's frequent air force patrols into Taiwan's regional airspace, and the United States' continuing supplies of advanced defense equipment to Taiwan, has raised worries that the island could become a flashpoint between the two superpowers.

Relations between the two sides' militaries have ebbed sharply since former US Defense Secretary James Mattis visited Beijing for talks on opening better channels of communication in June 2018.

Those discussions did not bear fruit, and Mattis' successor Mark Esper was unable to set up a meeting with his counterpart last year.

Austin and Wei were expected to have an opportunity for informal talks in early June at the annual Shangri-La Dialogue Asian security summit, but the event was cancelled last week due to ongoing Covid-19 concerns.