Royal biographer Angela Levin criticised Prince Harry and Meghan Markle after the couple's recent visit to New York.
Commenting on their trip , the royal expert said the couple is setting themselves up to be as important as heads of state and heads of government.
The Duke and Duchess of Sussex visited the United Nations in New York on Saturday to meet with Secretary-General Antonio Guterres during the 193-member world body's annual gathering of leaders.
"It was a lovely meeting," Markle told reporters as the couple left U.N. headquarters.
Harry and Meghan were in New York to attend the Global Citizen Live concert in Central Park later on Saturday, which aims to push for greater action to combat climate change and urge rich countries to share one billion doses of COVID-19 vaccines with nations most in need.
Taking to Twitter Levin said, "H and M are setting themselves up to be as important as heads of state and heads of government. They are not."