SINGAPORE - Dressed in a sober, dark suit, US Vice-President Kamala Harris took the bull by the horns on Tuesday (Aug 25) when she broached a topic that has cast its shadow over her South-east Asian tour.

"I'm speaking about Afghanistan, because I am aware that as I stand here today, the eyes of many around the world are on Afghanistan," she said at the start of a speech on US policy in the Asia-Pacific. "So before I begin my comments, I will talk about that."

The contentious subject of Afghanistan had come up several times on Monday, with American journalists shouting questions at Ms Harris just before the start of a bilateral meeting at the Istana.

She did not answer, but took several questions afterwards at a joint press conference with Prime Minister Lee Hsien Loong. Ms Harris faced a third barrage of shouted queries at Changi Naval Base later that day, but did not respond.

In her remarks on Tuesday, the Vice-President reiterated the Biden administration's position even as she sought to shift the focus back to her current trip.

"It is also imperative that as we address developments in one region, we continue to advance our interests in other regions - including this region," Ms Harris said.

"This region is critically important to our nation's security and prosperity," she added, citing statistics that underpin America's alliances and partnerships.

US exports to the Indo-Pacific support four million American jobs. The US conducted nearly US$2 trillion (S$2.7 trillion) worth of two-way trade with the region in 2019.

The US is determined to strengthen its economic engagement with the region, the Vice-President said, as she announced her country's offer to host the Asia-Pacific Economic Cooperation forum in 2023, the third time the US would chair the 21-member grouping.

She was speaking to politicians, academics and other public figures at Gardens by the Bay's Flower Field Hall, where glowing lights in red, white and blue were strung overhead.

In the audience were Senior Minister and Coordinating Minister for National Security Teo Chee Hean, Foreign Minister Vivian Balakrishnan and Leader of the Opposition Pritam Singh.

Veteran diplomats such as Mr Kishore Mahbubani and Ambassador-at-Large Chan Heng Chee - Singapore's longest-serving ambassador to the US - were also among the guests, who were asked to arrive about 1½ hours before Ms Harris was to speak, for registration and security clearance.

Following the Vice-President's speech, Prof Chan moderated a dialogue on American foreign policy with three US officials in the Vice-President's delegation.

Meanwhile, Ms Harris took part in a separate discussion on supply-chain resilience with Trade and Industry Minister Gan Kim Yong, as well as business leaders from the US and Singapore.

As the Delta variant of the virus that causes Covid-19 hits manufacturers around the world, parents are beginning to hear these words of caution, Ms Harris said: "If you want to have Christmas toys for your children, now might be the time to start buying them, because the delay may be many, many months."

Ms Harris capped her visit to Gardens by the Bay with a tour of the Flower Dome conducted by the Gardens' chief executive Felix Loh, who showed her the Singapore-grown hybrid orchid named after former US president Barack Obama and his wife, which was displayed alongside the new hybrid named after the Vice-President on Monday.

Despite the brevity of their visit there, Ms Harris and her delegation could not have missed the signs of America's appeal to Singaporeans and many others in the region at the ordinary, day-to-day level - signals of the strong, enduring relationship she spoke about.

All-American burger chain Shake Shack's newest outlet, its seventh in Singapore since arriving here in 2019, is right outside the Flower Dome, and although the store has yet to open, its lights were turned on and a sign said: "Our team is busy training today".

A recently opened Starbucks cafe and a McDonald's store - both chains have well over 100 outlets each in the Republic - are also located in Gardens by the Bay.

And more than 100 glass sculptures - some of which members of the US press travelling with Ms Harris noticed and posed with - by American artist Dale Chihuly are currently decorating the Gardens in a special exhibition that ends in October.

The Vice-President and her entourage left for Vietnam on Monday night after three days in Singapore, following a 3½-hour delay that US officials said was due to an "anomalous health incident" in Hanoi.

In Vietnam, she is scheduled to meet government leaders to discuss issues of mutual interest, such as regional security and the Covid-19 pandemic, before flying back home to the US on Thursday.