Ukraine said on Friday it would not launch an offensive against pro-Russia separatists controlling two regions in the east, as fears grow of a major escalation in a long-running conflict.
The statement came after fighting between the Ukrainian army and separatists intensified in recent weeks and Russia massed troops on the border.
"The liberation of the temporarily occupied territories by force will inevitably lead to the death of a large number of civilians and casualties among the military, which is unacceptable for Ukraine," Ruslan Khomchak, chief of the general staff of the Ukrainian Armed Forces, said in a statement.
He accused Moscow of using "intimidation and blackmail by military force" to exacerbate the situation.
"Ukraine is supported by the entire civilized world. We are not alone in the face of the enemy," Khomchak added.
The White House said Thursday the number of Russian troops at the border with Ukraine was now greater "than at any time since 2014," when war in eastern Ukraine first broke out after Russia annexed the Crimean peninsula.
Amid the intensifying fighting, Ukraine's President Volodymyr Zelenskiy on Thursday visited the eastern frontline, where he spent the night.
"Our country's fate is determined here," Zelenskiy said on Facebook, while images released by his office showed him in the trenches clad in a helmet and bulletproof vest, shaking hands with soldiers.
Zelenskiy, who has urged NATO to speed up his country's membership into the alliance to support Ukraine, said Thursday he had visited positions where Ukrainian troops were killed and wounded in recent weeks.
He said 26 Ukrainian soldiers had been killed since the start of the year, compared to 50 in all of 2020.
The conflict in Ukraine's mainly Russian-speaking east has claimed more than 13,000 lives since 2014.