Tánaiste Eamon Gilmore has warned against the West providing arms to Syrian rebels.
The Minister for Foreign Affairs made his comments following the claims by al-Qaeda that it had merged with an Islamic militant group fighting President Basher al-Assad's troops.
Mr Gilmore said: "The more arms and the more military equipment that is piled into that country the more dangerous it becomes.
"It underlines the need to ensure that the Syrian situation does not become more militarised."
Mr Gilmore warned that an increasingly militarised situation could prolong the conflict for "a very long time".
Earlier this week, al-Qaeda in Iraq claimed it had merged with al-Nusra, a radical Jihadist group credited with scoring military successes against the regime of Mr Assad.
Mr Gilmore said: "Clearly there are forces which are of a very extremist nature who are now seeking to exploit the conflict in Syria and that is a matter of very considerable concern.
"Again it goes back to the necessity to get a political solution to the crisis in Syria."
Speaking in Brussels at the beginning of a negotiation process between the Irish Presidency of the EU and the European Parliament over the EU seven-year budget, Mr Gilmore said he was very concerned about divisions within the Syrian opposition and that there was no coherent organisation among the various factions.
He said recent developments, including the reported merger between al-Nusra and al-Qaeda, underlined the need for "a strong UN position" on Syria.
The Tánaiste said: "Countries which are delaying a strong UN position need to change their view on that."
China and Russia have so far blocked a fresh UN resolution on Syria in the Security Council.
Britain and France have been arguing for a relaxation of the arms embargo on Syria in order to provide weapons to the opposition groups fighting to overthrow the Syrian regime.
Mr Gilmore said: "There are two dimensions to this, the question of Assad and what he is doing, and the attacks he is making on his own people, and the necessity of a change which will allow for the Syrian people to chose their own future.
"Into the mix of course also comes the interest of very extremist groups who perhaps have other agendas."
G8 ministers call for 'greater humanitarian assistance'
The Syrian crisis was also discussed by G8 foreign ministers at a meeting in London.
In the final statement, the ministers "called for greater humanitarian assistance and for improved and safe access to the Syrian people by humanitarian agencies in co-ordination with all parties to the conflict".
US Secretary of State John Kerry met Syrian opposition leaders in London yesterday to discuss ways to step up non-lethal aid to the rebels.
However, there was no mention of assisting the rebels in today's G8 statement.
Elsewhere, discussions between the UN and Syria's government on a possible investigation into the alleged use of chemical weapons in Syria have reached an impasse, UN diplomats have said.
Syria and the United Nations have been exchanging letters for weeks, but the two sides are far from agreement on how the investigation should be run, diplomats said on condition of anonymity.
Syria has asked the UN only to investigate what it says was a rebel chemical attack near Aleppo last month.
The opposition has blamed President Assad's forces for that strike and also wants the UN team to look into other alleged chemical attacks by the government.