Russia is ready to send a second humanitarian aid convoy to eastern Ukraine "even tomorrow", Kremlin spokesman Dmitry Peskov said on Wednesday, after an earlier convoy that entered Ukrainian territory last week without Kiev's permission.

Ukrainian President Petro Poroshenko criticised Russia's first humanitarian convoy, which raised tensions between the West and Moscow, and said he was concerned about Russia's intent to dispatch a second one.

When asked by journalists about plans for a second Russian convoy to eastern Ukraine, where government forces are fighting pro-Russian rebels, Peskov said: "It will happen soon, the Russian side is ready to do it even tomorrow."