New York, Nov 30 (IANS): Thousands of revellers gathered in the Rockefeller Centre here to watch the annual lighting of the world's most famous Christmas tree, the media reported.

Mayor Bill de Blasio flipped the switch at around 9 p.m. on Wednesday to illuminate the 75-foot-tall, 12-tonne Norway spruce with 50,000 multi-coloured lights and the iconic Swarovski star, more than two weeks after the tree arrived in Rockefeller Plaza from State College, Pennsylvania, reports NBC News New York.

This year's lighting ceremony featured performances by popstars Gwen Stefani, Seal, Jennifer Nettles, Train and the Pentatonix.

The tree will be lit every day from 5.30 a.m. to 11.30 p.m. until January 7, 2018, except for Christmas Day, when it will stay lit for 24 hours.

Additional security measure were deployed in the wake of last month's truck attack in Tribeca.

The annual holiday tradition started in 1931.

This year's tree is the 86th to sit over the Rockefeller Centre rink.

After the holiday, the tree will be donated to Habitat for Humanity, an international non-profit working on poverty housing. It will be made into lumber and used for home building.