Queen Elizabeth II on Monday addressed the United Nations climate change summit via video, saying that "the time for words has now moved to the time for action", The Associated Press reports.

The 95-year-old was due to attend the event in person in Glasgow but delivered a recorded video after doctors advised her to rest for two weeks.

"It is the hope of many that the legacy of this summit - written in history books yet to be printed - will describe you as the leaders who did not pass up the opportunity; and that you answered the call of those future generations," said the Queen.

"That you left this conference as a community of nations with a determination, a desire, and a plan, to address the impact of climate change; and to recognize that the time for words has now moved to the time for action," she added.

The Queen paid tribute to her late husband, Prince Philip, who died at the age of 99 earlier this year, recalling how he had warned an academic gathering in 1969 about the need to tackle the threats from pollution.

"If the world pollution situation is not critical at the moment, it is as certain as anything can be that the situation will become increasingly intolerable within a very short time," she quoted him as saying.

The Queen said she was particularly happy to welcome leaders to the summit because "the impact of the environment on human progress" was a subject close to his heart.

The Queen last week cancelled her attendance at the COP26 UN climate conference in Glasgow, following "advice to rest" from doctors following an overnight hospital stay.

Days earlier, the Palace revealed that The Queen had spent one night in hospital for “preliminary investigations” before returning to Windsor Castle the next day.

On Friday, Buckingham Palace announced The Queen has been advised to rest for at least the next two weeks, accepting doctors' advice to cut back on her busy schedule.