Kate Middleton: All the pictures as Princess of Wales and William arrive in Boston for their long-awaited US Royal tour

The Prince and Princess of Wales have flown to Boston for the Earthshot Prize awards now at risk of being overshadowed by a race row engulfing the future king’s godmother.

William thanked the US city for agreeing to host his environmental awards and for the tributes its citizens paid to his late grandmother the Queen, minutes after landing and being greeted by the governor of Massachusetts Charlie Baker and his wife Lauren.

But in the UK the fallout was continuing from the comments made by Lady Susan Hussey, who had repeatedly questioned a black British-born domestic abuse charity boss during a Buckingham Palace reception about where she “really came from”.

She has since resigned from her honorary role as one of three Ladies of the Household and apologised.

The prince is understood to agree it was right for Lady Susan to step down from her role with the royal household, with a Kensington Palace spokesman telling reporters in the US ahead of the Waleses’ three-day trip to Boston: “Racism has no place in our society.”

The spokesman said he spoke to William before he boarded his commercial flight and the heir to the throne was aware of the comments he would later make to the media.

Speaking about Lady Susan, the spokesman added: “The comments were unacceptable, and it is right that the individual has stepped aside with immediate effect.”

William and Kate have travelled to the US to stage, on Friday, the second Earthshot Prize awards ceremony, dubbed a “World Cup” moment by Hannah Jones, the Earthshot Prize’s chief executive.

Soon after landing, William said in a written statement: “On this, our first overseas visit since the death of my grandmother, I would like to thank the people of Massachusetts and particularly of Boston for their many tributes paid to the late Queen. She remembered her 1976 bicentennial visit with great fondness.

“My grandmother was one of life’s optimists. And so am I. That is why last year we launched the Earthshot Prize with the ambition to create a truly global platform to inspire hope and urgent optimism as we look to save the future of our planet.

“To the people of Boston, thank you. I’m so grateful to you for allowing us to host the second year of the Earthshot prize in your great city. Catherine and I can’t wait to meet many of you in the days ahead.”