KIEV, Nov. 19 - The West should not ease pressure on Russia over its role in Ukraine's conflict even if it cooperates with the Kremlin to fight terrorism, a senior Ukrainian diplomat said on Thursday.

Western countries imposed sanctions on Russia last year in response to its annexation of Crimea and support for pro-Russian separatists in Ukraine. But there have been signs of a diplomatic thaw in the wake of the deadly Islamist attacks in Paris.

French President Francois Hollande, who has discussed increasing coordination of military action in Syria with Russia's Vladimir Putin, will pay the first bilateral visit to Moscow by an EU leader in six months next week.

"A rapprochement between the West and Russia to fight terrorism is possible but not at the expense of Ukraine," Ambassador-at-Large Dmytro Kuleba told Reuters in emailed comments.

"Making compromises with Russia on Ukraine will mean the acceptance of the illegal use of force in Europe and will therefore have devastating consequences for pan-European security and international law."

NATO and the West accuse Russia of supporting separatists in Ukraine with weapons and troops, a charge the Kremlin denies.

Some of Russia's neighbors worry that European resolve to maintain pressure on the Kremlin over Ukraine could waver, leading to the easing of sanctions when they expire in January.

German Chancellor Angela Merkel has said sanctions will remain in place until a peace agreement is fully implemented.

In eastern Ukraine the guns were mostly silent in September and October, but the Ukrainian military reported six soldiers killed over the weekend.

"There has been a marked increase in ceasefire violations ... The ceasefire is very shaky at its edges," said Alexander Hug, deputy chief monitor with the Organization for Security and Cooperation in Europe's mission in Ukraine.

He said many recent attacks were with heavy artillery and weapons that were meant to have been withdrawn from the front line under a peace plan designed to end a conflict that has killed more than 8,000 people since April 2014. (rt/ez)