European Union leaders have expressed caution about the peace deal hammered out for eastern Ukraine.
Meeting in Brussels on February 12, EU leaders warned the cease-fire must be respected before any scaling back of sanctions against Moscow can be considered.
French President Francois Hollande said it was "very important" to keep up the pressure for there to be peace in Ukraine.
Hollande was speaking upon his return from Minsk, Belarus, where he helped broker the pact that included a cease-fire, withdrawal of heavy weaponry, and broad autonomy for Ukraine's east.
"Our trust in the goodwill of President [Vladimir] Putin is limited. It is why we have to maintain our decision about sanctions," said EU President Donald Tusk.
The EU has a February 16 deadline on whether to extend visa bans and asset freezes on 19 more Russians and Ukraine separatists and 9 entities.
That depends on if and how the latest truce will be implemented on the ground.
The EU already has 132 individuals and 28 entities on its blacklist, and targets Russia's energy and financial sectors with economic sanctions for their roles in the conflict in eastern Ukraine.
"We didn't discuss any new sanctions but we didn't decide also about postponing the sanctions," Tusk said.
EU diplomats have been reported as saying the 19 new Russians and Ukrainians will be added on February 16.
On the latest Minsk deal, EU leaders were slow to express optimism.
A September peace deal and cease-fire -- also brokered in Minsk -- broke down within days amid accusations that Moscow continued to boost the Ukrainian separatists.
Even German Chancellor Angela Merkel, who joined Hollande to broker the deal, had limited expectations.
"It is a glimmer of hope," she said. "No more, no less."
British Prime Minister David Cameron said he was looking to President Putin for real change to turn it into something more.
"We should be very clear that Vladimir Putin needs to know that unless his behavior changes, the sanctions we have in place won't be altered," Cameron said.
Lithuanian President Dalia Grybauskaite said "we've already had a bad experience of not implementing Minsk one. I think that until March there will be no discussion about lifting any kind of sanctions."
Under the deal, Ukraine will trade broad autonomy for the east for control of the Russian border by the end of the year.
The cease-fire is due to begin on February 15.