Ukrainian officials fear Russia may be using the aid mission to get equipment to rebels whom Kiev and the West claim are backed by Moscow. Russia insists the aid is destined for people in the cities in the east of Ukraine which are under attack from government forces.

Ukraine and Russia struck a deal ­allowing the lorries in, accompanied by the Red Cross, if Ukrainian border guards and customs agents approved the cargo.

However, the Kremlin now says Ukraine is using military tactics to stop the supplies getting through.

The Russian Foreign Ministry said: “We draw attention to the sharp intensification of military actions by Ukrainian ­forces with the obvious goal to block the route, agreed upon with Kiev, of the ­humanitarian convoy from the Russia-Ukraine border to Lugansk.

“Those nurturing such criminal plans are taking huge responsibility for their consequences.” The caravan of 280 trucks were parked on the Russian side of the border as the machinations continued.

Ukraine said its artillery destroyed part of a Russian armoured column which entered its territory on Friday night and said its forces later came under shell fire from Russia.

However, Russia said the report was “some kind of fantasy” and raised its own concerns about activity by the US-led Nato defence alliance near its borders.

In a call to US Defense Secretary Chuck Hagel, Russian Defence Minister Sergey Shoygu said Moscow was “seriously concerned” by increased Nato ­activity and called for a ceasefire to get aid into Ukraine. Nato said there had been a Russian ­incursion into Ukraine and accused it of destabilising the area.

The Secretary-General, Anders Fogh Rasmussen, said: “It confirms the fact that we see a continuous flow of weapons and fighters from Russia into eastern Ukraine and it is a clear demonstration of continued Russian involvement in the destabilisation of eastern Ukraine.

German Chancellor ­Angela Merkel phoned Mr Putin to urge he halt the flow of arms and fighters into Ukraine, while China’s President Xi Jinping also called for a political solution. Kiev and its Western allies have ­repeatedly accused Russia of arming rebels and sending undercover forces into Ukraine.

Ukrainian President Petro Poroshenko briefed Prime Minister David Cameron on the incident.

The Kremlin said Ukrainian and Russian chiefs of presidential staff met in Russia on Friday, while the Ukrainian foreign minister said he would meet his Russian counterpart in Berlin today.