Chinese Premier Wen Jiabao left Beijing Wednesday afternoon to attend the leaders' meeting of the UN Climate Change Conference in Copenhagen on Dec. 17 and 18.

Wen's entourage includes the heads of the Foreign Ministry, the National Development and Reform Commission, the Research Office of the State Council and the Premier's Office.

Premier Wen will address the summit, elaborating on China's stance and proposals on tackling climate change and promoting international cooperation, said a statement from the Foreign Ministry.

Wen would also meet with some state leaders and directors of international organizations on the sidelines of the summit.

At a regular press conference Tuesday, Foreign Ministry spokeswoman Jiang Yu said that if the talks came across any resistance or difficulties, it could be mainly attributed to developed countries' back-pedalling on the critical issues of mitigation, technology and funds.

Noting the conference had entered a crucial phase, Jiang said contradictions and divergences still existed while some achievements had been made in the talks.

China maintained the key to a successful conference lay with developed countries showing political sincerity, continuing to undertake substantial mid-term quantified emission reduction targets and fulfilling their obligations on providing assistance to developing countries, said Jiang.

Jiang called on developed countries to face up to their responsibilities and obligations.

The Chinese government always adopted active and constructive attitudes towards the Copenhagen conference on climate change, said Jiang.

She also said the vast number of developing countries had a consistent and clear-cut stand on major questions of principle.