Northern Ireland will have to bring in 2000 officers from other parts of Britain to police a G8 summit next year. The event will be held at Lough Erne golf resort near Enniskillen, County Fermanagh on 17 - 18 June.
The BBC reports 10,000 police officers were on duty when a G8 summit was held at Glenagles golf resort in Scotland seven years ago.
No event of this magnitude has ever been held in Northern Ireland before.
A BBC correspondent says a massive security operation will be required, but the Police Service of Northern Ireland are well used to dealing with a high level of threat. They are also experienced in dealing with large demonstrations.
No more than 10% of the force in will be allowed to take leave between 10 June - 12 August next year, with priority given to those with school age children.
Police also expect to have to deal with the kind of large scale protests. Officers from other police forces will include units to deal with any violent protests and specialist search teams.
This year's summit took place at Camp David in Maryland, USA.
The G8 event will be followed in August by the World Police and Fire Games, which are expected to attract 25,000 visitors from 70 countries.