The Taoiseach says Ireland will not be buying aircraft carriers or fighter jets under a new EU defence deal.
There have been concerns PESCO (Permanent Structured Cooperation) might undermine Ireland's neutrality.
The deal would see EU countries who sign up work together on issues of defence.
European officials say it the aim of the project is "to jointly develop defence capabilities and make them available for EU military operations".
A number of opposition groups here in Ireland have criticised the proposals in recent days.
People Before Profit's Richard Boyd Barrett has claimed the deal "would commit Ireland to taking billions away from solving the current housing and health emergencies to spend on weapons".
Sinn Féin spokesperson on defence Aengus Ó Snodaigh suggested PESCO was 'totally at odds' with Ireland's neutrality, adding: "I believe that even a cursory investigation of the criteria and implications of PESCO will show that it is not in Ireland's interests militarily, financially or otherwise."
However, Taoiseach Leo Varadkar says there will not be an issue with protecting our neutrality.
He told deputies: "We have a long-standing tradition of non-alignment and neutrality, one that I and this Government will defend because we believe our non-alignment and neutrality makes us stronger and gives us more influence around the world. PESCO, for us, is going to be something different than it perhaps is for other countries."
He added: "We will only opt in to certain into certain programmes and certain parts of PESCO that we want to be involved in - for example counter-terrorism, things like cybersecurity, peacekeeping.
"What we're not going to do... we're not going to be buying aircraft carriers, we're not going to be buying fighter jets, we're not going to be shopping around military trade fairs for any of these things. That's not in our interest."
He acknowledged that spending will rise - but pointed out that the Government had already committed to an increase in defence spending in its 2015 'white paper on defence'.
