So strict is censorship of the June 4,or"liusi"anniversary that many young Chinese don't know students were killed in the centre of Beijing.
The Australian government has declined to comment on the speech.
Chief executive of the Perth USAsia Centre,Gordon Flake,said Wei responding to the Tiananmen question was unexpected,and showed the level of confidence of the Chinese military.
"He was saying'we solved the problem',in other words,our pressure works,"says Flake,who was in the audience.
In his speech,Wei delivered a strong message warning Taiwan not to seek independence from China,and against"foreign interference in the Taiwan question".
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As the Trump administration has increased its official interactions with Taiwan's government,Wei said"any underestimation of the PLA’s resolve and will is extremely dangerous. We will strive for the prospects of peaceful reunification with utmost sincerity and greatest efforts,but we make no promise to renounce the use of force."
On the South China Sea,a potential flashpoint between the US and China,Wei said China had built defence facilities on islands and reefs for self defence purposes. An international tribunal has ruled the islands are not Chinese territory.
He took a swipe at Donald Trump's America First trade policy and said:"If the US wants to talk,we will keep the door open. If they want a fight,we will fight till the end."
Wei's speech was unapologetic,said Flake."If you assume they want others to bow to their will,that message was pretty clear."
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"It is useful because so often words are couched in fluffery and you don't get a real expression of Chinese power. It will make it a lot harder for others to say China is just benign."
A day earlier,acting US defence secretary Patrick Shanahan had attacked China over its"aggressive behaviour"in Asia. Shanahan told the conference the US would compete with China in the region but"competition does not mean conflict".
Bonnie Glaser,a director at the Washington-based Centre for Strategic and International Studies,said Wei didn't try to strike a conciliatory tone."He was especially tough when addressing issues related to sovereignty,"she said.
Glaser said China had sent a defence minister this year because it had previously"struggled to shape the narrative"at the regional defence summit."China’s confidence is growing and they see the benefits of high-level engagement as outweighing the risks,"she said.
Talk at the ShangriLa summit was dominated by the China and US,Flake said.
"The volume and unpredictability of the Trump-Xi contest and tensions in trade has everyone in the region alarmed and they have pulled back from talking about the broader region."
Wei sits on the Central Military Commission,however the commission's vice chairmen and its head,Xi Jinping,hold the real power over the People's Liberation Army.
Australia's new Defence Minister Linda Reynolds spoke at the summit,days into her appointment.