As many as 100 heads of state have confirmed they will attend the 15th meeting of the Conference of Parties, or COP15, which begins Monday in the Danish capital. More than 34,000 people have applied to attend the meetings , according to a report of CNN. Non-government organizations have been told some of their members will have to wait outside, while registration has closed early for journalists after 3,500 applied for access. Speaking at a "curtain-raiser" press conference on Sunday, Yvo de Boer, Executive Secretary of the United Nations Framework Convention on Climate Change (UNFCC), said: "Time is up." "Over the next two weeks government have to deliver a strong and long term response to the challenge of climate change." He said the level of commitment so far from developing and developed countries to reduce their emissions was "unprecedented." "Never in the 17 years of climate change negotiations have so many different nations made so many firm pledges together," he said.