Workers in Beirut decorate a Christmas tree with the message 'Merry Christmas and Happy New Year' in three languages: English, French and Arabic.
David Cameron, the British prime minister, turns on the Christmas tree lights at No 10 Downing Street in London.
Hundreds of people gather on the traditional Christmas market of Frankfurt, Germany, that was opened with the lighting of the tree.
Thai workers decorate a giant Christmas tree in a shopping mall in Bangkok.
People gather in front of the 30-metre high tree during the lighting ceremony in central Sofia, Bulgaria.
An employee of Japanese jeweller Tanaka Kikinzoku Jewelry unveils a 150 million yen (£1.2m) Christmas tree in Tokyo.
Visitors walk by a giant Christmas pyramid at the Christmas market in Berlin.
A worker installs a steel tree outside a shopping mall in Beijing.
The Rockefeller centre Christmas tree in New York City.
A street vendor dressed as Minnie Mouse sells balloons by Puerta del Sol Square's Christmas tree in Madrid.
A Christmas tree built of Lego bricks is on display at St. Pancras International station in London.
David Oakley, curator of the Christmas display for the Royal Collection, puts the finishing touches to a tree that is suspended from the ceiling at Windsor Castle.
The giant tree in Strasbourg's Christmas market.
A trumpeter plays during the illumination of the Christmas tree and opening of the Christmas market in Prague.
Fireworks explode over an 85-metre-long floating Christmas tree at the Lagoa Rodrigo de Freitas neighbourhood in Rio de Janeiro.
An illuminated tree stands in front of the Brandenburg Gate in Berlin.
Fireworks light up the sky to launch the Christmas tree display along a bay walk in Palawan city, Philippines.
The White House tree is displayed in the Blue Room of the White House in Washington.
A Norwegian Christmas tree lights up Trafalgar Square.
The National Christmas Tree is pictured with the White House in the background in Washington DC
A girl poses for photographs in front of a Christmas tree decorated with teddy bears in Seoul, South Korea.