King and Queen lay flowers at 9/11 Memorial in New York

The importance of the 9/11 attacks had been raised by King Charles in his speech to the US Congress on Tuesday.

He had called on US lawmakers to maintain support for Nato and had given the example of how Nato members had rallied to help the US in the wake of the 9/11 attacks.

“This atrocity was a defining moment for America and your pain and shock were felt around the whole world,” said the King.

And he told Congress the “same unyielding resolve is needed for the defence of Ukraine”.

The trip to New York, the third day of their four-day visit, will also have a lighter moment.

The Queen, a campaigner for literacy and reading, is bringing her own literary figure to donate to New York Public Library.

Since 1987, the library has had on display the original stuffed toys from the 1920s that inspired the Winnie the Pooh stories.

But since the 1930s, the toy of Roo, the baby kangaroo, has been missing.

A replacement Roo has been brought by the Queen on the flight from the UK, with the toy made by the same firm that made the originals.

The Queen has promoted literacy through her Queen’s Reading Room project – and the charity’s CEO, Vicki Perrin, who has also travelled to New York, warned on Wednesday that we are in a “reading crisis”.

She highlighted the social benefits brought by improving rates of literacy and reaching, which she said had “transformative benefits on mental health, brain health and social health”.

Later on Wednesday, the King will go to see an education and healthy food initiative in Harlem.

And the King and Queen will attend a reception for the creative industries, which is expected to attract some famous faces.