Members of the UN Security Council on Tuesday still failed to reach agreement on the language of the draft statement over the Iran nuclear issue after almost three weeks of contentious talks.

Ambassadors from the United States, Britain, France, Russia and China, which are the five veto-wielding permanent members of the Council, held the latest round of consultation Tuesday afternoon without reaching a deal.

"Ministers are getting together in Berlin on Thursday and I think for their purposes and ours we are trying to reach agreement before that," U.S. Ambassador John Bolton told reporters, hoping the council members would meet on Wednesday.

Meanwhile, British Ambassador Emyr Jones Parry admitted that there were still "one or two really difficult issues" ahead if his colleagues decided to finally finish the text by Thursday.

UN Secretary-General Kofi Annan said that he believed negotiations between Iran and others are still possible, but stressed that "the Iranians will have to heed the advice of ElBaradei and convince the international community that their intention is only for peaceful uses of nuclear energy." Foreign ministers from Britain, China, France, Germany, Russia and the United States will meet in Berlin on Thursday over Iran nuclear issue.

Last week, senior officials from the above nations held talks in New York on Iranian nuclear program, but did not reach any agreement.