Prince Harry and his wife Meghan Markle will co-chair a fundraising concert urging more vaccinations that will air on May 8, as the Queen returned to royal duties following the funeral of her husband Prince Philip.

The Duke and Duchess of Sussex will help lead Global Citizen’s effort to deliver COVID-19 vaccines to medical workers in the world’s poorest countries.

The pair will appear at Vax Live: The Concert to Reunite the World, to be taped on Sunday at SoFi Stadium in Los Angeles and air on US broadcasters and YouTube on May 8, anti-poverty non-profit Global Citizen announced on Tuesday (US time).

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Harry and Meghan are also leading an effort to raise money for the vaccine-sharing program COVAX, which hopes to produce $US19 billion ($A24 billion) to pay for the vaccines for medical workers.

Global Citizen bills itself as a movement calling on “world leaders, corporate leaders, and philanthropists to do their part” to end extreme provert by 2030.

US President Joe Biden and Vice President Kamala Harris will also appear during the broadcast as part of the We Can Do This initiative to increase confidence in COVID-19 vaccines.

French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau and Croatian Prime Andrej Minister Plenkovic will also appear at the concert, which will be hosted by Selena Gomez and headlined by Jennifer Lopez.

Foo Fighters, Eddie Vedder, J Balvin and H.E.R. are also set to perform, with hosts Chrissy Teigen, David Letterman, Gayle King and Jimmy Kimmel and actors Ben Affleck, Nomzamo Mbatha, Olivia Munn and Sean Penn also set to appear.

Earlier, Buckingham Palace released pictures of a smiling Queen conducting engagements by videolink with foreign diplomats.

The 95-year-old monarch held audiences with the new ambassadors for Latvia and Ivory Coast.

The Queen carried out the engagements from her Windsor Castle home to the west of London, where Philip’s funeral was held two weeks ago and it was the first since a period of official royal mourning ended.

It was, however, not the first official duty since the death of her husband of more than seven decades. She hosted several audiences in the week that followed.

-with AAP