While the leaders of eight of the world's most powerful countries will meet at the Lough Erne Golf Resort near Enniskillen, two major protests are planned for Belfast on Saturday.
Thousands are expected in the city to attend the demonstrations, one of which is against world hunger and the other organised by trade unions.
UTV understands that key sites, including Belfast City Hall and the Stormont estate, are under 24-hour police surveillance as a precaution.
Businesses like Citibank, Starbucks and the New York Stock Exchange offices have also stepped up their security.
Other key locations are Belfast International Airport, where all the leaders will be flying into, and Belfast city centre, where the US President Barack Obama will stop off at before going on to Fermanagh.
These are simply precautionary measures to give us confidence and to reassure the community that Belfast is a safe place and is very much open for business over the next number of days.
Chief Superintendent Alan McCrum, PSNI
"If we look at the history of other G8 events, there has been a level of protest particularly around key economic sites, as well as major iconic and political sites," PSNI Chief Superintendent Alan McCrum said.
"So from a Belfast point of view, we wanted to be satisfied that we have police resources out well in advance to minimise the risk of attack on any of those economic or major iconic sites.
"That being said, there is nothing at this point to indicate that that will in fact happen."
Thousands of PSNI officers, backed up by 3,500 public order police from England and Wales will be patrolling, while 900 gardaí will mount a major border security operation.
A specially erected fence currently surrounds the luxury Lough Erne resort in Enniskillen and overhead, there's a no-fly zone in the skies - PSNI helicopters and unmanned surveillance drones being the only exceptions.
An air corridor linking the city to Co Fermanagh, as well as the skies over the resort, will be off limits due to the summit.
The exclusion zones will not affect scheduled flights into and out of the George Best Belfast City Airport and Belfast International Airport - but passengers have been warned to expect significant traffic disruption due to the police checkpoints which will be set up on roads in the surrounding areas.
No-fly restrictions over Lough Erne will be put in place between 5pm and midnight from next Sunday to Tuesday.
The air corridor route from Belfast to Enniskillen will be out of bounds on Monday between 7.30am and 3pm and from on Tuesday 1pm to midnight to facilitate the departure of the VIPs.
The same strict limits will also be in place over Belfast.
Flying clubs and light aircraft pilots have been warned they must adhere to the bans.
A seven-mile stretch of the lough has been also shut and police boats are presently on patrol.
Assistant Chief Constable Alistair Finlay said that the PSNI are prepared for every eventuality.
"Currently our estimation of any people causing trouble is fairly low.
"We are prepared for people coming and causing some degree of trouble. We're ready should the unfortunate eventuality of trouble appear.
"We're prepared for that, but everyone we've been engaged with want this to be a great event for Northern Ireland."
He also warned those travelling to Northern Ireland with the intention of causing disorder not to come.
Speaking on the ongoing dissident threat, the senior police officer said: "We've nothing to suggest that dissidents will let up.
"We expect something all the time. That's our normal business - that's the sad reality of Northern Ireland.
"The sad background to Northern Ireland has seen the tempo of attacks predominantly on my officers and security personnel. There's nothing to suggest that this is going to stop."