The 25 EU nations were set Tuesday to 'strongly condemn' the nuclear testing announced by North Korea and urge Pyongyang not to repeat its actions.
EU foreign ministers meeting in Luxembourg were also to announce that a UN resolution containing sanctions against North Korea would be immediately applied.
In draft conclusions drawn up by ambassadors for endorsement in the ministers' meeting, which also covers a raft of issues from Iran to Georgia, the EU "strongly condemns the testing of a nuclear explosive device," announced by Pyongyang on October 9.
The North Korean move "poses a danger to regional stability and represents a clear threat to international peace and security," the document said.
The EU "will fully implement the provisions" of the UN Security Council resolution following the nuclear test, according to the conclusions which were to be formally approved by the EU foreign ministers later in the day.
North Korea said on Tuesday that the new UN resolution imposing sanctions on the country was a "declaration of war" and warned it would strike back at any nations that try to tighten the screws on its regime.
In its first reaction since the UN Security Council voted unanimously Saturday to punish the North for its tests, Pyongyang said having a nuclear weapon was its right and completely rejected the Council's decision.
The EU, in its draft, calls on North Korea "to abandon all nuclear weapons and existing nuclear programmes, and to comply with its obligations" under the nuclear non-proliferation treaty.
These include submitting all its nuclear activities to the UN nuclear watchdog IAEA.
The draft EU text further calls on Pyongyang "to refrain from conducting any further nuclear test or missile launch, and to re-establish its commitments to a moratorium on missile launching".
"It is important to signal to the North Koreans that any new nuclear tests will not be accepted," German Foreign Minister Frank-Walter Steinmeier told reporters ahead of the Luxembourg meeting.
"Particularly about North Korea, it is not only the European union, the whole international community is united," said British Foreign Minister Margaret Beckett.
A second nuclear test would be a sign that "North Korea is going out of its way to be as provocative as they possibly can, she added.
Stressing that North Korea's actions add to the risks of proliferation worldwide, the EU "calls for redoubling efforts to strengthen all aspects of the international system against proliferation of WMD (weapons of mass destruction)."
The UN sanctions, which mentioned no recourse to military options, imposed an arms embargo on North Korea and an embargo on nuclear and missile technology as well as "luxury products" and introduced inspections of all cargo in and out of North Korea.