The World Police and Fire Games in Belfast has attracted more interest than the previous event in New York, it has been claimed.
Organiser John Tully said more than 1,000 athletes from 33 countries had already signed up for the competition next August.
"We are greatly encouraged that on the day registration opened more than double the numbers reached on the first day of registration for the 2011 New York games," said Mr Tully.
The World Police and Fire Games is one of the largest multi-sports events in the world. Up to 10,000 competitors and 15,000 supporters are expected to travel to Northern Ireland for the games which will run between August 1 and 10.
More than 3,500 volunteers will be recruited.
Belfast Visitor and Convention Bureau director Mary Jo McCanny said accommodation bookings had gathered pace.
Kevin Smyth, general manager at Ten Square in Belfast city centre said the hotel had been booked up within 24 hours of registration going live. He added: "Belfast will be buzzing in August 2013."
More than 57 sports will feature in 42 venues in Belfast and across Northern Ireland. The Mary Peters track in south Belfast has been given a multimillion-pound upgrade in preparation for the games.
Northern Ireland is the third European host for the games.