Russian Foreign Minister says it is essential to prevent the destruction of the US-Russia cease-fire agreement for Syria.<br/><br/>Sergey Lavrov told the UN General Assembly that it was vital to support UN resolutions calling for an end to the fighting in Syria and for a political settlement. Lavrov said there must be an unbiased and impartial investigation of airstrikes that killed Syrian soldiers in Deir el-Zour and bombings in and around the northern city of Aleppo. <br/><br/>Lavrov said the Syria conflict cannot be resolved without the suppression of the Islamic State group and al-Qaida-linked fighters. <br/><br/>US Secretary of State John Kerry said he had met Mr Lavrov earlier in the day and that there was a little bit of progress on resolving differences on Syria.