Australia did not send a minister to the conference, and observers say the delegation of diplomats has been forced to stick to a limited brief set down by Canberra. This includes not making any new commitments to financially help poor nations deal with climate change – a critical issue at the talks.

Countries have also been concerned about statements by the Prime Minister, Tony Abbott, that appeared to narrow conditions under which Australia would adopt a more ambitious 2020 emissions target than the 5 per cent cut currently offered.

Japan has also been a focus of complaints after it dramatically scaled back the ambition of its 2020 emissions reduction target during the talks. Ms Molewa said: "We are deeply concerned about recent announcements by Japan and Australia to significantly reduce their commitments.

"Taken together with uncertainties around finance, this sends a very negative signal about the sincerity and commitment of these parties," she said.

Like many UN climate summits before it, the Warsaw talks have been bogged down in divisions between major developed and developing countries over who is most to blame for global warming, and who should pay.