Putin's spokesman Dmitry Peskov brushed off questions that the governments agreed on a deal for natural gas that excluded a requirement that Ukraine join a regional customs union, consisting of Russia, Belarus and Kazakhstan.
"At the moment we cannot officially confirm that there is an agreement," Peskov told the Interfax news agency. "In case such an agreement is recorded by the two sides, we will naturally announce this immediately."
Ukraine has tried to revamp a 2009 natural gas deal that broke a disruption of service from Russian energy company Gazprom. Former Ukrainian Prime Minister Yulia Tymoshenko is serving a seven-year prison sentence after being convicted on charges she overstepped her authority in that deal, which current Ukrainian officials say is too costly.
Gazprom last week sent state energy company Naftogaz a $7 billion bill for natural gas it didn't import last year under a "take-or-pay" contractual agreement.
Ukrainian Justice Minister Oleksandr Lavrynovych has said he hopes the issue can be resolved amicably.
Ukraine has looked to reserves like shale natural gas to break Russia's grip on the energy sector.