Pentagon officials have flown to Australia to for "emergency talks"
to express their frustration over the Port of Darwin sale
and Canberra's reluctance to stand up to Beijing.

Last year, the port hosted 102 naval vessels, according to its annual report, and was the point of arrival for US Marines on rotation through Darwin. Pentagon officials now want assurances from Australia on security arrangements at the port and better systems to ensure the breakdown in communication doesn't happen again.

The US officials also expressed concerns over Australia's lack of interest in sending naval ships to join Washington's so-called "freedom of navigation" operations in the South China Sea.