Witnesses said the convoy of more than 260 trucks had set out from a military depot in the southern Russian city of Voronezh after having spent the night there. The convoy appeared to be headed towards the eastern Ukraine city of Luhansk, which is held by pro-Russian separatist rebels.

Civilians caught up in the fighting between rebels and government troops in parts of eastern Ukraine were said to be in urgent need of humanitarian aid.

More than 200,000 residents of Luhansk are estimated to be in particularly urgent need of potable water, with no running water in the city for the past 11 days. There is also no electricity and other essential supplies in local shops are said to be sparse at best.

However, it remained unclear on Thursday morning how or where the convoy might cross the border into Ukraine.

On Wednesday, a spokesperson for Ukrainian President Petro Poroshenko said the convoy would be allowed to cross the frontier only if the trucks were first inspected by Ukrainian border guard and customs officials, as well as representatives from the Organization for Security and Cooperation in Europe.

Moscow has dismissed suggestions from Kyiv that it could be using the convoy as a cover either to deliver weapons to pro-Russia rebels, or to actually launch an invasion of Ukraine, saying it had coordinated the dispatch of the goods with the International Committee of the Red Cross (ICRC).

ICRC guidelines not met

The ICRC has confirmed that Russia has provided it with a "general list" of goods being transported by the convoy, including basic necessities such as bottled water, food and generators.

However an ICRC spokeswoman said a general list did not meet the organization's guidelines for maintaining its neutral role in conflict zones.

"A number of important issues still need to be clarified between the two sides, including border crossing procedures, customs clearance and other issues," spokeswoman Anastasia Isyuk told the Reuters news agency.

Meanwhile, the United Nations said on Wednesday that the death toll in the fighting in eastern Ukraine had climbed above 2,000.

A spokeswoman for the UN High Commissioner for Refugees said the daily average number of casualties had climbed to 70 from the 60 reported in previous months, since the conflict broke out in mid-April. These include Ukrainian soldiers, pro-Russia separatist rebels and civilians.

pfd/rc ( dpa, AP, Reuters)