Ukrainian troops have held up an advance by Russian forces from the northeastern city of Izyum towards nearby Sloviansk, Oleksiy Arestovych, a Ukrainian presidential advisor said on Wednesday.
"They have focused their forces there, that is where they are trying to advance, but so far they are not succeeding," he said in a video address.
Arestovych also said that Ukrainian forces in the besieged city of Mariupol have been holding out, despite persistent Russian attacks on the Azovstal steel plant.
(Reporting by Aleksandar Vasovic; Editing by Jon Boyle)