Environment ministers are holding talks at the UN climate conference in Copenhagen amid threats of large-scale protests by environmental groups.

哥本哈根举行的联合国环境会议上，各国环境部长主持讨论了由环境保护组织提出的大规模环境威胁。

Activists, angered by logistical issues and a lack of progress on a deal, have vowed to disrupt proceedings.

The White House said President Barack Obama, who will join world leaders in Copenhagen later in the week, is confident of reaching a deal.

Talks are deadlocked僵持 over emission cuts and financial aid for poorer countries.

For the last two mornings, thousands of campaigners have queued for hours to gain access to the conference venue地点，场所 - many unsuccessfully.

Now, with ministers and their aides joining the conference, the organisers have slashed削减 the number of other delegates allowed in.

A spokeswoman from the Climate Justice Action group says demonstrations amounting to "mass civil disobedience不合作主义，非暴力反抗" are planned for Wednesday.

The groups says some 15,000 delegates have been effectively "locked out" of the summit by being refused accreditation委派，鉴定资格 or experiencing long delays in their applications.

UK Prime Minister Gordon Brown, who is already in Copenhagen, told reporters on Tuesday that it was a critical moment.

"This is a very important moment for the world," Mr Brown said.

"It is possible that we will not get an agreement and it is also true that there are many issues to be sorted out. But I am determined... to do everything I can to bring the world together."