Mobile phone providers in the Irish Republic could be asked to cut signals during the G8 summit amid fears terrorists may use them to detonate bombs.
The Irish government's defence minister Alan Shatter warned that there was a "real danger" lives could be lost in such an event.
"It is possible that terrorist groups may try to use the occasion of the summit to, at the very least, garner publicity for themselves," Mr Shatter said. "This is not to ignore the very real danger of the loss of life if such a device were successfully detonated."
Details of First Lady Michelle Obama's travel will be announced at a later date but she is widely expected to return to the Republic and visit her husband's ancestral homeland in Co Offaly. Other politicians to attend the G8 conference will include German chancellor Angela Merkel and UK Prime Minister David Cameron.
It is believed the meeting on June 17 and 18 will generate up to £40 million for the local Northern Ireland economy.
Mr Shatter said the summit, at the Lough Erne golf resort on the outskirts of Enniskillen, created a real necessity for legislation to give the Government the power to ask phone companies to cut or limit signals. He revealed the plan as he announced changes to the new Money Laundering and Terrorist Financing Bill.
"The purpose of these amendments will be to allow for direction to issue to mobile phone service providers to cease service provision in a limited area in order to prevent death or damage to property," the minister said. "The provision will contain safeguards to ensure that any interference to services is limited to the extent necessary to deal with the threat."
Elsewhere, a major public march and rally will be held in Belfast the weekend before the G8 summit. Trade unions and campaign groups like Amnesty International and Friends of the Earth are organising a Fairer World Festival to coincide with the event.
Mr Shatter announced the amendments to the new legislation - which is yet to be passed into law - at a parliamentary committee meeting.