After Russian troops registered progress in eastern Ukraine, Kiev on Saturday reiterated that the situation remains difficult on the front lines.
The commander of the defence forces, General Sergei Naev, said the situation in the combat zones was "difficult" but that Ukrainian forces still controlled the situation.
Russian reinforcements in Donetsk
He also added that Russian forces, which he described as an enemy, were strengthening their forces and resources in Donetsk province, particularly in the Lugansk region, in order to carry out search operations in specific areas, in an effort to surround Ukrainian forces.
In a video during his visit to Ukrainian positions, he stressed that his country's forces were fortifying their defensive lines in the north-eastern regions of Kharkiv and Zaporgia in the south.
"You may have to withdraw"
Serhi Jayday, governor of the eastern Lugansk region, had previously declared that "Ukrainian forces may have to withdraw from the last pocket of resistance in Lugansk to avoid capture", with the rapid progress of Russian forces in the east, in a major change in the developments of the three-month-old fighting.
This Ukrainian withdrawal may bring Moscow closer to its stated goal of taking full control of the Donetsk and Lugansk regions of Donbass, particularly after field gains in those areas, which together form the territory's important basin to the east.
Russia's progress in the east followed a Ukrainian counter-offensive that pushed the Russians back away from Kharkiv this month. But Moscow prevented Ukrainian forces from attacking the back rows of Russian supply lines for Donbass.
In March, Moscow announced the launch of the second phase of its military operation, which began on February 24th on Ukrainian territory, in order to take control of Donbass, and to open a land corridor connecting the eastern regions of Crimea, which it annexed to its territory, in 2014.