The warning shot comes as US Vice President Kamala Harris is set to travel to Vietnam later this month to "strengthen relationships and expand economic cooperation". Also, US Secretary of Defense Lloyd Austin completed a two-day visit to Hanoi on Thursday where he tried to strengthen political ties between the two nations. Vietnam disputes China's vast 'nine-dash line' claim over the South China Sea, which encroaches on Hanoi's maritime territory.

       Beijing has been constructing artificial fortified islands in the maritime region and prohibiting ocean-going vessels from free passage through it.

       On Thursday, US secretary of Defence Lloyd Austin said in a speech to the International Institute for Strategic Studies that "Beijing's claim to the vast majority of the South China Sea has no basis in international law".

       "That assertion treads on the sovereignty of states in the region," he added.

       Beijing is not happy about the US visit to its southern neighbour.

       The Chinese state-run Global Times stated: "Austin's visit was the first to Vietnam by a high-ranking US official since US President Joe Biden took office in January."

       However, it then took comfort in its assertion that "no actual progress has been made in US-Vietnam bilateral relations".

       The online news platform then suggested when it comes to Washington's diplomacy in South East Asia, "the US seems to be obsessed with being two-faced".

       According to the Chinese Communist Party (CCP) mouthpiece, this duplicity is expressed by the US simultaneously levelling "unreasonable sanctions to provoke China" and saying that it is "committed to pursuing a constructive, stable relationship with China".

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       The tabloid insists "the US aims to portray itself as the guardian of regional security and regional countries' interests" but that this is only a ploy to create problems for Beijing's ambitions in the South China Sea.

       Li Kaisheng, a research fellow and deputy director at the Institute of International Relations of the Shanghai Academy of Social Sciences, speaking to the Global Times said: "The US says it does not want Southeast Asian countries to take sides, but it is asking other countries to side with it to jointly contain China.

       "Vietnam is clear about such intent, and it knows better than any other regional countries the risk of being involved in the campaign."

       The Global Times ended its op-ed by warning the US that if it "continues to stir up the South China Sea issue and add fuel to the fire, forcing Southeast Asia to get on its chariot against China, it may be disappointed no matter how hard the US manipulates".

       Both the US and China have had costly wars against Vietnam in the 20th Century, both powers ultimately failed in their objectives.