The Queen has paid tribute to the “resilience and determination” of 9/11 survivors, as Boris Johnson said the terrorists had “failed to shake our belief in freedom and democracy”.
In a tribute at Windsor Castle, the American anthem and other songs were played by the Band of the Welsh Guards in front of the acting US ambassador.
The prime minister recorded a message that played at a memorial event at London’s Olympic Park, where a memorial forged from the steel of Ground Zero is on display.
He said that September 11, 2001 had become “in President Roosevelt’s words after Pearl Harbour, a ‘date which will live in infamy’.”
Sixty-seven Britons were among the nearly 3,000 people who died.
Mr Johnson, who was born in New York, said the terrorists had “tried to destroy the faith of free peoples everywhere in the open societies which terrorists despise and which we cherish”.
However, he said they had “failed to drive our nations apart, or cause us to abandon our values, or to live in permanent fear”.
“The fact that we are coming together today – in sorrow but also in faith and resolve – demonstrates the failure of terrorism and the strength of the bonds between us,” he said.
Mr Johnson also mentioned the recent withdrawal of British troops from Afghanistan – 20 years after they were sent there to prevent the country again being used as a base to organise terror attacks.
“Recent events in Afghanistan only strengthen our determination to remember those who were taken from us, cherish the survivors and those who still grieve and hold fast to our belief in liberty and democracy, which will always prevail over every foe,” Mr Johnson concluded.
The Queen also sent a message to President Joe Biden.
She said: “As we mark the 20th anniversary of the terrible attacks on September 11 2001, my thoughts and prayers – and those of my family and the entire nation – remain with the victims, survivors and families affected, as well as the first responders and rescue workers called to duty.
“My visit to the site of the World Trade Centre in 2010 is held fast in my memory.
“It reminds me that as we honour those from many nations, faiths and backgrounds who lost their lives, we also pay tribute to the resilience and determination of the communities who joined together to rebuild.”
Archbishop of Canterbury Justin Welby said it was “still hard to articulate the loss that terrible day brought”.
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