Beijing is sending its defence minister for the first time since 2011 to the so-called Shangri-La Dialogue, which is also attended by acting US Defence Secretary Patrick Shanahan and a host of top military officials from around the world.

Both countries have been vying for influence in the region, which hosts potential military flashpoints such as the South China Sea, Korean Peninsula and the Taiwan Strait -- as well as among its fastest-growing economies.

The US and China are also embroiled in tit-for-tat trade war, kicked off by President Donald Trump raising tariffs against Chinese goods last year.

Shanahan will meet his Chinese counterpart, General Wei Fenghe, late Friday to discuss areas where the nations might cooperate, according to officials.

Washington has been pushing back against Beijing's militarisation of the South China Sea.

A top US top general said earlier this week that Chinese President Xi Jinping had reneged on promises by building "10,000-foot runways, ammunition storage facilities, routine deployment of missile defense capabilities, aviation capabilities" on reclaimed land.

"So clearly they have walked away from that commitment," said General Joseph Dunford, chairman of the Pentagon's Joint Chiefs of Staff.

Wei's attendance at the Shangri-La Dialogue -- an annual gathering of global defence officials organised by the International Institute for Strategic Studies think-tank -- is being taken as a sign that China is not backing away from the dispute.

"The Chinese want to be here to say their side of the story," Shawn Ho, associate research fellow at the S. Rajaratnam School of International Studies in Singapore told AFP.

"Definitively, we are seeing more competition between the US and China in various fields -- not just traditional fields, but also in technology.

"The US and China are seemingly competing in more fields nowadays and I think this is something that we have to watch very carefully."

Shanahan said he wanted to identify areas where the countries could cooperate.

"We'll probably talk about things I think are important for us to be transparent and candid about," he told reporters Thursday, as he flew into Singapore from Indonesia.

Shanahan is expected to flesh out Washington's strategy in the Pacific region, where both the US and China are vying for influence, during a talk on Saturday.

Wei will address the conference on Sunday, with a source from his delegation saying the speech will outline China's role in global security and US-China ties -- as well as addressing the territorial disputes in the South China Sea.

"The 'China threat' is a non-existent issue. We are here to correct that misconception," added the source, who did not want to be named.

Beijing's defence policy remains defensive, they said.

"We will not cede even a single inch of Chinese territory. Similarly, we have never sought, and will never want any territory belonging to others," the source added.