On Tuesday (July 26), the United States accused China of upping its "provocations" against rival claimants in the South China Sea and claimed that due to its "aggressive and irresponsible behavior," a significant incident or accident was just a matter of time.

There is "a clear and upward trend of PRC provocations against South China Sea claimants and other states lawfully operating in the region," according to Jung Pak, deputy assistant secretary for East Asia at the State Department, speaking to a US research group.

She reported to the Center for Strategic and International Studies that Chinese aircraft were increasingly engaging in dangerous intercepts of Australian aircraft in international airspace above the South China Sea and had interfered with marine research and energy exploration operations in the Philippines' exclusive economic zone in three separate incidents in recent months.

Ely Ratner, assistant secretary of defense for Indo-Pacific Security Affairs, claimed later at the same event that there had been "dozens" of events involving the Chinese military in the South China Sea in the first half of the year, a dramatic rise over the previous five years. "Beijing is systematically testing the limits of our collective resolve," he said.

"In my view, this aggressive and irresponsible behavior represents one of the most significant threats to peace and stability in the region today, including in the South China Sea. And if the PLA continues this pattern of behavior, it is only a matter of time before there is a major incident or accident in the region," referring to China's armed forces, he said.

The remarks came ahead of a phone call that is expected to take place this week between President Joe Biden and Chinese President Xi Jinping. The call is expected to center on ways to keep the growing US-China strategic rivalry from turning into a war, particularly over the island of Taiwan, which is self-ruled by China and claims it as its own.

Additionally, they arrived before meetings of partners and foreign ministers from Southeast Asia, including the U.S., that will take place in Cambodia the following week.

China claims almost the whole South China Sea, and Pak has referred to these claims as "expansive and unlawful." She went on to say that China's "provocative actions" in pursuing such claims "contribute to regional instability, damage the economies of other claimant states, undermine the existing maritime order and threaten the rights and interests of all nations that rely on or operate in this vital waterway."

According to Pak, Washington has a "very complicated relationship with Beijing" and is not attempting to counter everything it is doing in Southeast Asia and the rest of the developing world.