A French air defence warship carried out manoeuvres with Irish naval vessels off Dublin Bay at the weekend as Ireland steps up defence preparations for the EU presidency.Ireland is expected to rely on French and British military assets, including naval ships, to provide security during the six-month presidency that begins on Wednesday.In preparation, the Defence Forces has increased co-operation with both countries in the maritime domain.On Sunday a French multipurpose frigate conducted manoeuvres in the Irish Sea about 22km east of Howth, security sources have said. Two Irish Naval Service vessels conducted manoeuvres nearby.The ships operated with their transponders turned off, meaning they were not visible on open-source ship tracking platforms. However, they were visible to passengers on civilian aircraft landing at Dublin Airport.The French ship’s presence was confirmed by satellite images reviewed by The Irish Times.The operation, which was not announced publicly, is designed to prepare for the EU presidency with Ireland hosting dozens of high-level meetings, some of which will require air defence systems that the Defence Forces do not possess.Military sources said French naval crews have been provided with tactical radios by their Irish counterparts to facilitate communication. This was required because the Irish Naval Service does not possess the Nato-standard communications systems used by the French.The French ship, which is equipped with advanced air defence radar and up to 32 anti-aircraft missiles, operated just outside of Irish territorial waters, which extend 12 nautical miles out to sea.[ Shotguns, helicopters and ‘airburst’ ammunition to guard against rogue drones during EU presidencyOpens in new window ]A Defence Forces spokesman said for operational security it “does not comment on the disposition of the Naval Service fleet”.The French embassy did not respond to requests for comment.Questions have been raised about the legal and constitutional implications of requesting military assistance from other nations, particularly if it involves the potential use of deadly force.Last week security officials held a meeting to discuss the legal implications of such a move. The meeting, which was first reported by The Journal, was attended by Attorney General Rossa Fanning who provided legal advice on the constitutionality of foreign militaries operating in Ireland.Separately, the Defence Forces has been stepping up measures to prepare for the presidency, including conducting anti-drone training and installing jamming devices at Casement Aerodrome where visiting dignitaries will land.Air Corps aircraft have been practising shooting down rogue unmanned aerial vehicles using machine guns while soldiers on the ground are receiving training in using shotguns to shoot down drones.However, anti-drone electronic warfare systems ordered for Irish naval vessels will not be in operation until January next year, after Ireland hands over the presidency.