UK PM to accompany King on tour of country

She was also present, along with six former prime ministers, senior bishops and several politicians, when Charles, 73, was officially proclaimed the UK's new king in a colourful ceremony laden with pageantry and tradition.

She later met Charles along with other senior ministers at Buckingham Palace.

"In terms of the prime minister's involvement, she will join the King as he leads the national mourning across the United Kingdom, attending services of reflection in Scotland on Monday afternoon, in Northern Ireland on Tuesday, and Wales on Friday," the spokesman told reporters.