Talks on humanitarian corridors for Mariupol failed, Vadym Denysenko, the adviser to the Interior Minister, said.

"The most critical situation now is certainly the city of Mariupol. There, unfortunately, it is not possible to agree on any humanitarian corridors and the situation there is quite critical, given that the city has been continuously shelled from Grad rocket launchers for the past five days," Denysenko said on the air of the Ukraine-24 TV channel on Friday.

He also said that the attempt of Russian occupiers in Kherson to distribute humanitarian aid to residents failed.

"Not just failed, but failed miserably. People simply do not come to KAMAZ vehicles with their "humanitarian aid," people ignore them, while they are not allowed to do pictures for Russian television they wanted to make," Denysenko said.