Visits by top American leaders, such as Vice-President Kamala Harris's trip to Singapore and Vietnam in a fortnight's time, are greatly valued and show that the US is investing the bandwidth and resources in the region, Prime Minister Lee Hsien Loong said yesterday.

Such high-level visits also signal that the United States has substantial stakes and interests to protect and advance, he added at the virtual Aspen Security Forum.

PM Lee also noted the US' renewed emphasis on multilateralism, and refocusing on its global network of allies and partners.

"There is a palpable sense of relief not just in the Asia-Pacific, but all round the world. Countries are looking for long-term strategic consistency from the US," he said. "They hope for a reliable and predictable US, which will provide a stable anchor for the international order, as it has done for so many decades."

Secretary of State Antony Blinken and Defence Secretary Lloyd Austin have visited Japan and South Korea, and Mr Austin was also in Singapore, Vietnam and the Philippines, PM Lee noted.

PM Lee, who was the keynote speaker at the two-day forum, said the US is in the region not just to ensure regional security and a balance of power, but also to drive trade and investment, and to grow the broad trans-Pacific relationship.

"The current mood in the US is not pro-trade, but there are many new opportunities for the US to cooperate with the region, for example in digital trade and green growth. So I hope the US will pursue them, and continue to play a major role in fostering an inclusive, rules-based world order."

The White House had announced last week that Ms Harris will visit Singapore and Vietnam this month to deepen the US' engagement with South-east Asia, but did not mention dates. The Straits Times understands the visit will take place from Aug 22 to 24.

In his remarks, PM Lee said it was unfortunate that the Covid-19 pandemic has not brought countries closer together, but often to the contrary, even as there has been some cooperation on issues such as vaccine multilateralism.

There was a scramble for critical supplies, like masks and personal protective equipment, and later vaccines, he said. "Internationally, the pandemic has spawned recriminations and finger-pointing - where did the virus come from, who is to blame, and so on. Domestically, populations in many countries felt growing anxiety and insecurity, which has fed nativist sentiments," he said.

His 50-minute session moderated by American journalist Evan Osnos touched on a variety of issues, from how US politics was viewed around the world, to the issue of Taiwan reunification, and possible areas of cooperation between China and the US.

Asked whether the reaction against globalisation will continue, PM Lee said the impact will be felt not just in physical and financial investments. The impact on the movement of people was "a very big factor in Brexit and it's not absent from any of our politics".

"And even in Singapore where we have a significant number of migrant workers as well as foreign professionals, it's a sensitive political issue, and we have to put a lot of effort into managing the relations and explaining to Singaporeans why this is necessary and how the issues can be managed," he said.

"At the same time, we explain to the foreign population here that their contributions and their economic efforts are appreciated."

PM Lee also shared his views on the US-China relationship, which he said has been more difficult in the last few years. In the US, there has been a deep, bipartisan shift in attitudes towards China, which extends into the population, he said. In China, attitudes have also become more assertive and robust.

China's strategic and economic influence has grown, he added, citing its more active international stance, seeking to reshape the international order to its advantage.

"It will be hard to reverse the present trend towards more troubled relations. But many countries still hope that the deterioration in the relationship can be checked.

"Because many US friends and allies wish to preserve their extensive ties with both powers. No good outcome can arise from a conflict," he said.

"It is vital for the US and China to strive to engage each other, to head off a clash which would be disastrous for both sides, and the world," he added.