EU High Representative and Vice-President Federica Mogherini's office made the statement while she was in New York for meetings around the UN General Assembly on Wednesday.
"The European Union reiterates its steadfast support for Iraq's unity, sovereignty and territorial integrity," it read. "Unilateral actions, such as the proposed referendum, is counterproductive and must be avoided."
The EU acknowledged the outstanding issues between Erbil and Baghdad.
"This should be done through a peaceful and constructive dialogue leading to a mutually agreed solution based on the full application of the provisions of the Iraqi Constitution," it added.
Individual EU nations, France and the UK, have taken part in efforts to convince Erbil to postpone the referendum and focus on negotiations with Baghdad – efforts that have so far been refused by the Kurdish leadership as inadequate alternatives to the plebiscite, the stated goal of which is independence.
Officials in Baghdad have also rejected international proposals.
Iraq's Vice President Nouri al-Maliki rejected a UN-sponsored initiative aimed at finding a solution on disputes between Baghdad and Erbil on Wednesday.
Maliki, who released a statement in his role as the head of Iraq’s ruling State of Law Coalition, said they reject an initiative by the UN Envoy to Iraq because it contains sections "in violation of the constitution in an explicit way.”
In particular, they rejected a section that calls for a time limited negotiating for talks, something he called a “pre-condition.”
The EU, however, expressed support for the UN effort. "The EU welcomes the UN initiative to facilitate a dialogue and offers its support to such a process if requested," read the statement from Mogherini.
The office of Jan Kubis, the UN Special Representative for the Secretary-General to Iraq, did not immediately respond to a request for details of the initiative.
