Putin offers support for Ukraine's cease-fire
While asking both sides to stand down, Russia's president ordered major military exercises.
But he warned that Ukrainian President Petro Poroshenko's blueprint for peace would not be viable without action to start peace negotiations.
The qualified Russian backing for Poroshenko's effort to halt the conflict was another in a series of shifting Kremlin moves and statements that leave unclear the level of Moscow's commitment to de-escalating the conflict.
Putin's conciliatory words came on the same day he ordered large-scale military exercises that NATO criticized as likely to raise tensions. U.S. officials also accused Russian troops of moving back into positions near the border with Ukraine's troubled east.
The statement said Putin supported Ukrainian President Petro Poroshenko's decision to order Ukrainian troops to observe a unilateral cease-fire starting Friday night.
But it added that Putin wanted to draw "attention to the fact that the proposed plan, without practical action directed at a beginning for a negotiating process, will not be viable or realistic."
Poroshenko bills the unilateral cease-fire as designed to inspire a wider peace plan that would include an amnesty for pro-Russian separatist fighters who disarm.
Further steps would include joint security patrols, a buffer zone on the border, early regional and parliamentary elections, protections for the language rights of people who use Russian as their main language, and eventually changes in the constitution to permit more regional self-government.
Ukrainian troops have struggled for weeks to suppress separatists who have seized buildings and declared independence in the eastern Donetsk and Lugansk regions near the border with Russia.
Ukraine and the United States have accused Russia of supporting the insurgency, including by permitting tanks to cross the border and wind up in the rebels' arsenal. Russia counters that it is not supporting the insurgents and Russians who have joined the fighting are doing so as private citizens.
U.S. and European leaders have called on Russia to play a constructive role in settling the conflict and halt what they say is support for the rebels. The United States and European Union have imposed financial sanctions on specific Russian officials but have held off on targeting entire economic sectors.
It remains unclear whether Russia can or will influence the pro-Russian fighters to de-escalate the conflict.