The Prince and Princess of Wales have met budding environmental tech entrepreneurs in Boston – and a little boy dressed as a familiar guardsman.

William and Kate’s three-day trip to the US to stage the Earthshot Prize has been overshadowed by the growing race row engulfing the future King’s godmother, which has left the monarchy accused of being institutionally racist.

Lady Susan Hussey has resigned from her role in the royal household and apologised after she repeatedly questioned Ngozi Fulani, a prominent black British-born domestic abuse charity boss, about where she “really came from” during a Buckingham Palace reception.

The prince remained focused on his environmental prize during his visit to Greentown Labs near Boston and issued a warning, saying: “For all of us the time is ticking.”

As he chatted to some of last year’s Earthshot finalists he praised them for their ground-breaking work, adding: “As time goes by I keep saying ‘come on we’ve got to move faster and faster’.”

The prince’s estranged brother, the Duke of Sussex, and his wife are not expected to attend the environmental awards on Friday but on the second day of the Waleses’ first overseas trip since the death of the Queen, the trailer for Harry and Meghan’s Netflix docu-series was released.

The one-minute film featured never-before-seen private photographs of the couple, who live in California, and in one section of the footage, Meghan appears to be wiping away tears while Harry sits and tilts his head right back, seemingly in distress.

A Kensington Palace spokesman has reiterated comments made ahead of the trip that they would not be “distracted” by other things this week and their focus today was on meeting communities and local people across Boston.

The couple looked relaxed and were greeted by cheers from the crowds as they arrived at Greentown Labs, a tech hub which has been nurturing a community of climate pioneers for more than a decade.

Greentown is believed to be the largest climate technology start-up incubator in North America, having supported more than 500 companies since being founded in 2011, which have created more than 9,000 jobs and raised more than 4 billion dollars in funding.

In a contrast to the drama in the UK, there was a lighter moment during the visit when the couple met eight-year-old Henry Dynov-Teixeira who was dressed as a guardsman in replica scarlet tunic and bearskin.

The youngster handed Kate a bunch of red roses and said he was “thrilled” to meet the royals in person.

Royal visit to Boston – Day 2
Henry Dynov-Teixeira, 8, dressed as a guardsman (Kirsty O’Connor/PA)

“I am going to scream and tell my best friend that I am now famous,” Henry added.

Hi mother Irina, who visited London this summer with her son, said: “He saw changing of the guard on a visit to London and wore it for Halloween.”

Later William praised the “incredible” work of Roca, a non-profit organisation supporting disadvantaged young people at risk of or involved with urban violence.

Royal visit to Boston – Day 2
The Princess of Wales meets well-wishers during a visit to Roca, in Chelsea, Massachusetts (Ian Vogler/Daily Mirror/PA)

When the couple visited the organisation they got a rousing welcome as they undertook their first walkabout of their US trip in Chelsea, a short drive from Boston, with one young woman collapsing in tears.

She did not want to give her name but repeatedly clasped Kate’s hand and thanked her for everything she did.

Later in an impromptu speech, William described the organisation’s work as “incredible” and said the team was inspirational, adding: “We have really enjoyed making this connection today.”

Royal visit to Boston – Day 2
The Princess of Wales meets a young child during the visit (Ian Vogler/Daily Mirror/PA)

Inside the organisation’s building the couple were introduced to Molly Baldwin, chief executive officer of Roca, who began her professional life as youth worker, founding the organisation in 1988 to work with a small group of high-risk young people.

William said: “It’s trying to get the message across that there’s a grey area between when you look at a young person and see a gap between the potential they have and the trouble they cause.

“As a society how do we tackle that? There is so much happens in between and there is so much potential there.”

Royal visit to Boston – Day 2
The couple met counsellors and clients at the centre (Ian Vogler/Daily Mirror/PA)

Sitting down with a group containing two counsellors and two young people who have been helped by Roca, the couple chatted more about the organisation’s work.

Jonathan Williams, 22, a candidate on the Young Men’s programme, had an awakening while serving time for an attempted robbery and is now, with Roca’s help, working to become an insurance brokers and is focusing on improving his self-image and helping others.

The prince and princess also popped into the creche for the children of young mothers who are being helped by the centre, sitting down to play with them.