Ukraine will not allow a Russian convoy of over 250 trucks, said to be carrying aid supplies, to enter the country, Arsen Avakov, the Ukrainian interior minister, said in a Facebook post Wednesday. The Russian convoy, which Moscow insists is carrying humanitarian aid to the war-torn regions of eastern Ukraine, is expected to arrive at the border by Wednesday evening.

Agence France-Presse, or AFP, reported that Ukrainian authorities plan to stop the trucks at the border, where the contents will be unloaded, screened and then carried into Ukraine with the help of the International Committee of the Red Cross.

“We will not allow (the convoy) to be accompanied by the Russian ministry for emergency situations or by Russian troops," Valeriy Chaly, deputy head of the presidential administration, told AFP.

Ukrainian Prime Minister Arseny Yatseniuk also reportedly hit out against Russia and called the dispatch of the aid convoy an act of “Russian cynicism.”

“First they send tanks, Grad missiles and bandits who fire on Ukrainians and then they send water and salt," he said on Wednesday, according to a Reuters report.

However, Russia has insisted that the convoy be allowed to its destination and demanded “maximum cooperation” from Ukrainian authorities, AFP reported Wednesday.

Ukraine and the United States have expressed fears that Moscow plans to use the cover of a humanitarian operation to embark on a military incursion in support of pro-Russian separatists in eastern Ukraine.

U.S. State Department spokeswoman Marie Harf had, on Tuesday, reportedly backed Kiev and said that Russia had “no right” to move into Ukraine unilaterally “whether under the guise of humanitarian convoys or any other pretext, without Kiev's permission.”