A team of several dozen Ukrainian customs and border service officials will inspect a Russian aid convoy parked provocatively just beyond its border.
The cargo will be inspected in the presence of representatives from the International Committee of the Red Cross.
Russia was reported to be prepared to present all necessary documentation and to hand over the cargo to the Red Cross.
The aid convoy of more than 200 trucks pushed up to the border yesterday but then stopped, poised to cross into rebel-held territory.
The Ukrainian government threatened to use all means available to block the convoy if the Red Cross was not allowed to inspect the cargo. An inspection would ease concerns that Russia could use the aid shipment as cover for a military incursion in support of Ukrainian separatists, who have come under growing pressure from government troops.
The United States has warned Russia that it needs to secure Ukraine's permission for the convoy to enter.
European Commission president Jose Manuel Barroso called Russian and Ukrainian leaders to arrange three-way consultations on ways to de-escalate the crisis.
Ukraine announced it was organising its own aid shipment to the war-wracked separatist region of Luhansk.
Complicating the dispute, Ukraine said yesterday it has gained control over a key town near Luhansk city, giving it the means to block the presumed route that the Russian convoy would take to the city.
The town, Novosvitlivka, lies about 25 miles from the border.
The Russian convoy set out yesterday morning from a military depot in the southern Russian city of Voronezh where it had been parked since late on Tuesday. Moscow says the convoy has 262 vehicles, including about 200 trucks carrying aid.
The white-tarpaulined trucks, some flying the red flag of Moscow and escorted by military vehicles, drove down a winding road through sunflower fields and then turned west toward the rebel-held border crossing of Izvaryne.
But about 17 miles from the border, the trucks pulled off and parked in a large field where dozens of beige tents had been set up. Drivers in matching khaki shorts and shirts piled out and appeared to be stopping for the night.
The route suggested Russia had decided not to abide by a tentative agreement to deliver aid to a government-controlled border checkpoint in the Kharkiv region, where it could more easily be inspected by Ukraine and the Red Cross.