Gardai have removed a number of protesters from the first session of the Consultative Forum on International Security Policy in Cork after they interrupted the opening address of Tanaiste Micheal Martin.
Mr Martin continued to speak to the audience at University College Cork as the demonstrators shouted slogans including: "No to Nato."
The minister accused the protesters of attempting to shut down debate, which he characterised as undemocratic.
The four-day forum on Irish security and defence policy began on Thursday amid criticism of the line-up of speakers from the opposition and president.
The aim of the event is to build public understanding and generate discussions on foreign, security and defence policies.
The Government said the forum, which also sits in Galway on Friday and Dublin on Monday and Tuesday, will include civilian and military experts and practitioners representing "a breadth of experience and views".
The triple-lock mechanism for foreign troop deployments and Ireland's neutrality are expected to be examined as part of the conversations on foreign and defence policy.
The proceedings are chaired by Professor Dame Louise Richardson, Oxford's first woman vice-chancellor, who was recognised in the UK's 2022 Queen's Birthday Honours for services to higher education.
The schedule includes panels on the global security environment and the European situation following the Russian invasion of Ukraine as well as discussions on cyber security and threats to critical infrastructure.
The Irish President said Ireland is "playing with fire" in a drift towards Nato.
In an interview with the Sunday Business Post, Michael D Higgins criticised the line-up of speakers at the forum, saying they comprised "the admirals, the generals, the air force, the rest of it".
Mr Higgins also referred to Prof Richardson as a person with a "very large letter DBE" (Dame Commander of the British Empire) after her name.
He has since apologised to her for the "throwaway" remark.
Opposition parties have also been critical of the Government's approach to the forum as well as the list of speakers.
Sinn Fein spokesman on Foreign Affairs and Defence Matt Carthy said an independent foreign policy "has served us well and that neutrality should be enshrined in the constitution".
"We cannot allow neutrality to be recast as a weakness by those who would have us further aligned to Nato.
"Ireland's neutrality is a strength. It is about showing leadership on the world stage, finding solutions, de-escalating crises and, where needed, contributing to peacekeeping missions.
"It is about ensuring our security in a turbulent world.
"While government have clearly sought to use this forum to reshape public opinion rather than facilitate a genuine public discussion, Sinn Fein will use the limited opportunity available to us to set out that neutrality has served Ireland well and will be crucial to allowing us to play a positive and constructive role in the world."
Solidarity TD for Cork North-Central Mick Barry said the forum had been loaded with speakers who support increased European militarisation and hold pro-Nato views.
However, Mr Martin has said there are "no predetermined outcomes" for the process.