The Ukrainian prime minister has responded to the arrival of Russian aid lorries in Ukraine, saying that Moscow must take the blame for anything that happens with the convoy.

Arseny Yatseniuk told journalists: “All responsibility lies with Russia only and with the Russian president personally after Russia violated all international treaties and refused to cooperate with the Red Cross.”

NATO Secretary General Anders Fogh Rasmussen was quick to criticise Russia, accusing Moscow of sending weapons into Ukraine.

In a written statement he said that NATO had seen “ transfers of large quantities of advanced weapons, including tanks, armoured personnel carriers and artillery to separatist groups in eastern Ukraine”.

Russian ambassador to the United Nations Vitaly Churkin said they had waited at the border for a week, but needed to deliver the aid.

“At times it seems that there is no clear chain of command in Kyiv because some assurances are given on a very high level and then others do not give the orders which are required to the border police to let the trucks in. That game could not continue indefinitely. We waited long enough and it was time to move.”

The Ukrainian and Russian presidents are due to meet EU officials on August 26 in Minsk, the capital of Belarus, to discuss the conflict in Ukraine.

However, no face to face meeting between Presidents Poroshenko and Putin is planned