Queen Elizabeth was "saddened" to hear about the shooting in Las Vegas.
The 91-year-old matriarch sent a message to President Donald Trump after she and her husband Prince Philip found out that around 60 people had died and more than 500 had been injured after a man opened fire at Route 91 Festival in Nevada over the weekend.
According to the Daily Mail newspaper, she said: "Prince Philip and I were saddened to learn of the terrible attack in Las Vegas. Our thoughts and prayers are with the victims and their families and those who have been injured."
The queen's sweet message comes four months after she used her annual birthday speech to reflect on the UK's "very sombre national mood" after it had been hit by "terrible tragedies" - including the terror attacks in Manchester and London and the devastating fire at London's Grenfell Tower - since the beginning of the year.
She said: "Today is traditionally a day of celebration. This year, however, it is difficult to escape a very sombre national mood. In recent months, the country has witnessed a succession of terrible tragedies.
"As a nation, we continue to reflect and pray for all those who have been directly affected by these events. During recent visits in Manchester and London, I have been profoundly struck by the immediate inclination of people throughout the country to offer comfort and support to those in desperate need.
"Put to the test, the United Kingdom has been resolute in the face of adversity. United in our sadness, we are equally determined, without fear or favour, to support all those rebuilding lives so horribly affected by injury and loss."