Premier Wen Jiabao denied the accusations that China acted arrogantly during the Copenhagen climate talks last year.
Wen said he learned that China was on an invitation to attend a small-group meeting with state leaders including US President Barack Obama, but he and the Chinese delegation was not actually invited.
Despite being uninvited, Chinese vice foreign minster He Yafei was sent to attend the meeting, but President Obama had not arrived yet.
Wen said "I almost didn't sleep during 60 hours' stay in Copenhagen and meet many state leaders, including discussion with Obama twice."
"China has made great efforts during the conference," Wen said.
Even when leaders began to leave the conference as the meeting was in difficulty, China was still making efforts to help reach an agreement and best resulted.