At a monthly press briefing in Beijing, China Defense Ministry spokesman Tan Kefei blamed the U.S. Thursday for "serious difficulties" in the bilateral relationship, highlighting the Biden administration's strategy of "comprehensive containment" against the country to maintain dominance in the region, according to Newsweek .

Kefei said the U.S., under the guise of freedom of navigation, in the South China Sea, displays its power by sailing warships and is creating instability in the region.

Kefei said: "At present, relations between China, the United States, and the two militaries face serious difficulties at an important juncture. The root cause is the U.S.'s obsession with hegemony and its Cold War and zero-sum mentality."

"The U.S. does not accept and will not allow or accommodate China as it grows stronger," he added. "It treats China as a strategic rival and security threat, implementing comprehensive containment and suppression of China while seriously undermining China's sovereignty, security and development interests."

The comments come as Vice President Kamala Harris is on her tour around Southeast Asia and has called for other countries to pressure Bejing for its actions in the South China Sea.

"We need to find ways to pressure and raise the pressure, frankly, on Beijing to abide by the United Nations Convention on the Law of the Sea, and to challenge its bullying and excessive maritime claims," said Harris.

Besides Harris, Defense Secretary Lloyd Austin said: "Beijing's claim to the vast majority of the South China Sea has no basis in international law."

The South China Sea is in focus because it's a resource-rich shipping lane that is the most vital route for commercial vessels globally. China continues to lay claim to all of the waters but other claimants, such as Vietnam, Malaysia, and the Philippines, have also claimed parts of the sea.

"[We] are not asking countries in the region to choose between the United States and China. In fact, many of our partnerships in the region are older than the People's Republic of China itself," Austin said.

Kefei said Austin's comments were "irresponsible and wrong."

Meanwhile, just north of the South China Sea is Taiwan. We reported Wednesday that Tokyo and Taipei are holding meetings to address Beijing's increasingly aggressive stance against Taiwan at the end of the week.