Russian Foreign Minister Sergei Lavrov is due to host the UN envoy for Syria, Staffan de Mistura in Moscow on Tuesday.

Their meeting comes as the United States charges that Russia, while agreeing to support a ceasefire, has done very little to rein in Syrian President Bashar al-Assad's forces around Aleppo. Russia says it will not ask the Syrian government to halt air raids on Aleppo as it believes they are helping to combat jihadist groups there.