Kate Middleton spends Valentine's solo

Liverpool - An eight-year-old boy stood in for Britain's Prince William on Tuesday, presenting his wife Catherine with Valentine's Day roses while the royal is deployed to the Falkland Islands.

The Duchess of Cambridge was visiting an alcohol-free bar for recovering addicts in the city of Liverpool in northwest England, ahead of a visit to nearby Alder Hey children's hospital.

Cheering crowds greeted the former Kate Middleton, 30, as she arrived wrapped up in a burgundy coat to visit the bar run by charity Action on Addiction.

Jaqson Johnston-Lynch, aged eight, was chosen to present the duchess with a bunch of red roses, a Valentine's Day card and a cupcake.

"I have wrote in the card 'Dear Kate, Happy Valentine's Day, I love you, from Jaqson'," he said.

A smoothie

Speaking just before Catherine's arrival at the charity, of which she is a patron, Jaqson said he had a speech prepared.

"I'm going to say 'Happy Valentine's Day, your Royal Highness. I'm sorry Prince William can't be here'," he said.

Once inside, Catherine helped to make a smoothie named "The Duchess" in her honour before being serenaded by the bar's resident choir, the Raucous Caucus Recovery Chorus.

The duchess has been taking the opportunity to expand her royal role during William's six-week deployment to the Falklands as a search-and-rescue helicopter pilot with the Royal Air Force (RAF).

She carried out her first solo public engagement last week when she visited a major exhibition of paintings by the late British artist Lucian Freud at the National Portrait Gallery in London.

Argentina, which claims the Falklands as its own, has condemned William's mission in the British-controlled archipelago as "a provocation" ahead of the 30th anniversary of the war the two countries fought over the islands.

Catherine and the prince married at a lavish ceremony last April which was watched by an estimated two billion people around the world.