TALLINN, Estonia (CNN) -

Ukraine's President announced progress on a ceasefire agreement Wednesday with Russia, but U.S. President Barack Obama greeted it with skepticism and Moscow downplayed it.

Obama, speaking in Estonia ahead of a NATO summit in Wales, said he was aware of the reported deal, as conflicting accounts emerged from Russia and Ukraine. But he said it was too early to see if all sides would follow through.

Any ceasefire effort has not worked up to now, he said, "either because Russia has not supported it or pretended it is not controlling the separatists" in eastern Ukraine.

"Having said that, if in fact Russia is prepared to stop financing, arming, training and in many cases joining with Russian troops' activities in Ukraine, and is serious about a political settlement, that is something that we all hope for," Obama said.

Meanwhile, France, a member of NATO, won't be delivering the first warship it is due to deliver Russia as part of a 2011 contract, the office of French President Francois Hollande said.

"The President of the Republic has noted that, despite the prospect of a ceasefire that remains to be confirmed and implemented, the conditions for France to authorize the delivery of the first (warship) are not authorized," the statement said.

Since mid-April, Ukrainian forces have been battling pro-Russian rebels in eastern Ukraine. Kiev and the West say the rebels are supported by Moscow -- a claim Moscow denies.

Ukrainian President Petro Poroshenko's office initially said he and Russian President Vladimir Putin had agreed to "a full ceasefire" following a phone call, but subsequently indicated they had agreed on a process that could lead to a truce.

"The conversation resulted in an agreement on ceasefire regime in the Donbas (eastern Ukraine region)," said the statement from the presidential press office. "The parties reached mutual understanding on the steps that will facilitate the establishment of peace."

Earlier, Putin spokesman Dmitry Peskov told CNN there was "no confirmation of a ceasefire because Putin cannot agree (to) a ceasefire because he is not party to the conflict.

"What was agreed were steps that would lead to a ceasefire. The important thing is to bring an end to the bloodshed and to stop the firing. Everyone is trying to de-escalate the conflict."

Peskov also said the longer term issue of constitutional reform in Ukraine was not discussed.

However, the spokesman told Russian state news agency Itar-Tass that Putin's view on possible ways out of the crisis "largely coincides" with that of Poroshenko.

Putin's roadmap

Russia's President presented his roadmap for a ceasefire to journalists Wednesday, the state-run RIA Novosti news agency reported.

Setting out his seven-point plan, Putin said both parties in the conflict must negotiate immediately and stop "any offensive military operations by the army, armed forces and self-defense groups of the southeast of Ukraine towards Donetsk and Luhansk." Russia routinely refers to the rebels as self-defense forces.

Putin called for Ukrainian troops to pull back to a distance that would mean they can't fire shells on communities. He also urged an end to the use of military aircraft against civilians and an exchange of all hostages.

The Russian President said the sides should "provide full and objective international control over the conditions for the ceasefire and monitoring of the situation."

Humanitarian corridors also should be opened to permit delivery of aid to communities in Donetsk and Luhansk, he added, and workers should get access so they can rebuild cities' infrastructure.

Ukrainian Prime Minister Arseniy Yatsenyuk dismissed Putin's roadmap as looking like a "rescue plan" for the rebels, and said Russia could not be trusted to stick to any agreement.

"This plan is yet another attempt to trick the international community on the eve of NATO summit and avoid the EU decision of the next level of sanctions against Russia," he said, according to the Cabinet's press office.

"Putin's real plan is to destroy Ukraine and renew the USSR."

Rebels question ceasefire

A rebel spokesman in eastern Ukraine expressed doubt a ceasefire could hold and demanded federal troops withdraw from the region, according to RIA Novosti.

An aide to another rebel leader, the DPR's First Deputy Prime Minister Andrei Purgin, told the news agency that Poroshenko's ceasefire move was unilateral and was "impractical" while there were still Ukrainian forces in the disputed region.