A cease-fire agreement between Russia and Ukraine set to start on Sunday was agreed upon Thursday with European markets reacting positively to the news, but analysts and experts are fearful the deal will go the same way of previous accords. After all-night negotiations, Russian President Vladimir Putin said he and his Ukrainian counterpart, Petro Poroshenko, agreed to the cease-fire and the withdrawal of heavy weapons from the eastern Ukraine region affected by the conflict between pro-Russian separatists and the Ukraine military. Read MorePutin: Leaders agree on Ukraine cease-fire

Ukrainian servicemen load rockets before launching them toward pro-Russian separatist forces outside Debaltseve, eastern Ukraine February 8, 2015. Alexei Chernyshev | Reuters

"You have to regard this deal as being very positive," Rob Carnell, chief international economist at ING, told CNBC, "but you have to see this being implemented on the ground." Putin said Ukraine agreed to constitutional reforms with control over the Russia-Ukraine border to be agreed with separatist leaders. The ruble gained ground on announcement, up 1 percent against the dollar and the RTS index rose 5.6 percent. The pan-European Euro Stoxx 600 Index also reacted positively to the deal.

Rebels placated?

Whether pro-Russian rebels in the east can be brought to heel is still a subject of debate for observers of the long-running conflict.

"As we've seen so many times before, that hasn't been the case. It's a question of whether the separatists in eastern Ukraine are fully under the control of Putin and will abide by this, and if they don't we could see this unraveling quite quickly," Carnell told CNBC's "Worldwide Exchange." Carnell said a positive outcome of the deal was that it put on ice the U.S. threat of arming Ukraine but, in all, the best perspective on the deal was to be "cautiously optimistic." Following the deal, Poroshenko said Kiev would reassert control of the joint border with Russia by the end of 2015, adding that the peace deal did not include federalization or autonomy status for pro-Russian rebels. Read MoreRussia in 'dire straits' and needs reform: FinMin

Christopher Granville, managing director of the Russia team at emerging market research firm Trusted Sources, agreed that the deal was a "necessary starting point." "It's not a sufficient condition for a resolution of what is ultimately a geopolitical confrontation going way beyond the horrible events going on in south-eastern Ukraine but it's a necessary condition for getting to a solution," he told CNBC's "Worldwide Exchange." "But there's chance now that the worst of this violence and the loss of life will be behind us," he added.

Putin ploy?

German Chancellor Angela Merkel, who, along with French President Francois Hollande helped broker the agreement, said there were no illusions that the deal would be easy, saying there was "very, very much work" still needed for Ukraine.

She added that Putin had put pressure on separatist leaders to agree to the cease-fire and that there was a "glimmer of hope" for Ukraine. Not everyone was convinced about the honorable intentions of Putin, however. One emerging market analyst said that the U.S. perspective on the deal was skeptical. "Just talking with U.S. guys, … the assumption is that this deal will inevitably unravel and Putin will blame untrustworthy Ukrainians, and hope to sideline any further sanctions as a result," Timothy Ash, head of emerging markets research at Standard Bank, said in a note following the deal. As the "contact group" (of representatives from Ukraine and Russia) were the signatories on the deal, Ash thought this would allow Putin to "say he was not party to it, if it goes belly up."