United Kingdom, May 31 -- Donald Trump has stepped in to headline the forthcoming America 250 celebration after a string of musical acts withdrew from the event.

The US president, 79, is now set to take centre stage at the Great American State Fair on the National Mall after several artists pulled out of the Freedom 250-organised celebrations marking the 250th anniversary of the United States - with the Republican claiming performers had got "the yips" over appearing at the festival.

The festival, scheduled to run from 25 June to 10 July, was initially announced with a line-up including Martina McBride, Young MC, C and C Music Factory, Bret Michaels, The Commodores and Morris Day of Morris Day and The Time.

However, more than half of t...