Queen Elizabeth II welcomed Chinese Premier Li Keqiang to Windsor Castle on Tuesday on a visit to Britain which aims to repair strained relations between London and Beijing.

Dozens of Chinese were waiting outside the mediaeval castle, west of London, to greet Li on the first full day of his three-day visit to Britain.

Queen Elizabeth, 88, welcomed the 48-year-old premier with a smile and a handshake as they met in the castle's White Drawing Room.

They were joined by Li's wife Cheng Hong, and Prince Andrew, the queen's second son, who works to promote the creation of skilled jobs in Britain.

Andrew, the Duke of York, greeted Li and his party when they arrived at Windsor Castle in limousines.

The Times newspaper reported last week that Beijing made a meeting between Li and the queen a precondition for the visit and threatened to call it off if it was not arranged.

Li was later to meet British Prime Minister David Cameron for talks at his Downing Street office, aimed at boosting economic links and warming ties that were frozen over Tibet.

Cameron's May 2012 meeting with the exiled Tibetan spiritual leader the Dalai Lama infuriated Beijing.

Li's visit marks the latest stage in a painstaking diplomatic rehabilitation effort and could lead to business deals worth �18 billion ($30.5 billion, 22.5 billion euros).

British energy giant BP has already said it will sign a deal worth around $20 billion (14.75 billion euros) over 20 years with Chinese state-owned peer CNOOC to supply China with liquefied natural gas.

Britain also announced an easing of visa restrictions for Chinese tourists and business people.

Li's trip to Britain is the first by a Chinese premier since his predecessor Wen Jiabao visited in 2011.

The last president to visit was Hu Jintao in 2005, in a trip dogged by protests by pro-Tibet and human rights campaigners.

The Free Tibet campaign group had written to Queen Elizabeth, urging her not to meet Li.

They claimed the meeting "does not appear to be in the interests of the monarchy, the United Kingdom, or those resisting oppression across the world".

Pro-Tibet campaigners demonstrated outside Downing Street, posing in handcuffs and waving placards reading "Free Tibet before free trade".