MOSCOW — Confusion swirled around the fate of an enormous Russian aid convoy as it apparently halted on Wednesday at a military base in the southern Russian city of Voronezh, temporarily suspending its march toward southeastern Ukraine.

Moscow and Kiev seemed headed toward at least a standoff over the convoy, with Russia saying it still expected the hundreds of trucks to be allowed across the border and Ukraine vowing that they would be barred. Later in the day, though, Kiev relented somewhat, with the office of President Petro O. Poroshenko saying it would allow the trucks to cross after they had been inspected by Ukrainian officials and monitors from the Organization for Security and Cooperation in Europe.

Throughout Wednesday, tensions rose in the absence of a clear statement from Russia about where the trucks were headed. Rumors began to fly that they would bypass the original point of entry, the Shebekino crossing, near Kharkiv and firmly in Kiev’s grasp, and head farther south to an area closer to Luhansk, where Russia and the separatist fighters it supports exert more control.

That would raise the possibility of the trucks entering the country against the warnings of Kiev and without the contents being examined by the International Committee of the Red Cross, which Russia has pledged to have oversee the aid delivery.