The importance of stable and constructive relations between the United States and China will be the focus of Prime Minister Lee Hsien Loong's keynote speech at an annual Asia defence forum on Friday.

At the Shangri-La Dialogue (SLD), PM Lee is expected to highlight the role Singapore and other small states can play in bolstering the world order, amid escalating tensions between the world's two biggest economies.

Trade talks between the US and China broke down in Washington earlier this month. Both sides have imposed heightened tariffs on billions of dollars worth of each other's imports. Washington has also blacklisted Chinese technology giant Huawei, restricting its dealings with US firms.

PM Lee will address defence ministers, military chiefs and top-ranking defence officials at the annual dialogue organised by the International Institute for Strategic Studies (IISS), which will take place at the Shangri-La Hotel from Friday to Sunday. He last gave the keynote address at the forum's 2015 edition.

IISS director-general John Chipman said: "Delegates from the region and beyond could not have a better-informed guide than PM Lee to the security challenges facing the region and to how concerned states may best ensure continuing stability."

Chinese Defence Minister Wei Fenghe will attend the forum - making him the highest-ranking Chinese official to attend the SLD since 2011, when former defence minister Liang Guanglie spoke at the event.

General Wei's speech will be scheduled a day after US Acting Secretary of Defence Patrick Shanahan speaks at the forum. The two are reportedly expected to meet on the sidelines of the gathering.