Ukrainian President Petro Poroshenko said his military is ready to return its heavy weapons to the front lines in eastern Ukraine, noting that Russian-backed rebels are still violating a cease-fire deal reached earlier this month.
Poroshenko said Friday Ukraine's army "is ready at any moment to stand up to the enemy."
He also said a military threat from the east will remain even if the truce holds, an obvious reference to Russia.
Meanwhile, a Ukrainian military spokesman said three government soldiers had been killed and seven wounded in the past day. That follows two consecutive days when no soldiers were killed.
Russian Foreign Minister Sergei Lavrov said there has been progress in the withdrawal of heavy weapons in eastern Ukraine. He stressed the importance of fulfilling other aspects of the truce, including key humanitarian issues and constitutional reform in the Donbas region of eastern Ukraine.
On Thursday, Ukrainian troops began withdrawing artillery from a front-line eastern village near the devastated town of Debaltseve, under the watchful eye of European monitors overseeing the cease-fire deal.
Military officials on Thursday showed reporters from the Reuters news agency trucks towing 100-millimeter guns from the village of Paraskoviyvka, as Ukraine acknowledged a marked reduction in rebel attacks in the past few days. Kyiv authorities, however, said its withdrawal timetable could be adjusted if army positions are attacked.
Separately, Russia's Interfax news agency quoted rebel spokesman Vladyslav Deyneho as saying separatists planned to complete their withdrawal of heavy weapons from frontline positions by March 4. He did not identify locations where those weapons will be repositioned.
In other developments Friday, officials in Spain said police arrested eight Spaniards suspected of fighting for pro-Russian rebels in eastern Ukraine. A statement said the eight were accused of various crimes.
Russia reduces spending, revises budget
Russian news agencies report that President Vladimir Putin has decided to cut the salaries of members of his administration by 10 percent.
Meanwhile, Reuters reported that Putin's government would ask parliament to allow it to spend up to 3.2 trillion roubles ($52.36 billion) from the country's reserve fund this year. That figure includes including 500 billion roubles already included in the budget.
Reuters said Russia is revising its budget due to oil prices being much lower than previously assumed, and because of the effects of sanctions imposed over the Ukraine conflict.
Foreign Minister Lavrov warned Western governments against imposing more sanctions on Moscow, which has been repeatedly accused of supplying arms and troops to rebels. Moscow has denied the accusations, saying Russians fighting alongside rebels during the 10-month rebellion are doing so as volunteers.
Speaking to reporters Thursday, Lavrov described the sanctions threats from Washington and Brussels as an attempt to "deflect attention" from details of the cease-fire. Lavrov also cited what he called "a lack of desire" in the West to back the truce deal negotiated by the leaders of Germany, France, Ukraine and Russia.
The war of words between Moscow and the West has intensified over the past week with U.S. Secretary of State John Kerry accusing Moscow of engaging in "the most overt and extensive propaganda exercise that I've seen since the very height of the Cold War."