U.S. Secretary of State John Kerry said Friday that Ukrainian President Viktor Yanukovych has not yet made sufficient concessions to end his nation's political crisis.
Kerry spoke from Germany where he will meet with Ukrainian opposition leaders on the sidelines of an international security conference.
Yanukovych says his political opponents are escalating the crisis, unlike his own government, which he says has fulfilled its obligations to end the standoff by replacing the prime minister and granting a conditional amnesty for arrested protestors.
But Kerry said the Yanukovych government still has work to do.
"The offers of President Yanukovich have not yet reached an adequate level of reform and an adequate level of sharing of the future so that the opposition can in fact feel that it could legitimately come to the table and form some kind of unity government," he said.
Kerry spoke to reporters in Berlin alongside German Foreign Minister Frank-Walter Steinmeir.
Speaking through a translator, Steinmeir said it is still unclear whether the Ukrainian president is willing to accept real change.
"My impression is that Yanukovych up until now still has not fully understood how serious the situation is as can clearly be seen by the nature of the offers that have been made," he said. "They have been made contingent on a number of conditions."
Ukrainian opposition leaders including politician Arseny Yatsenyuk and former boxing champion-turned-activist Vitali Klitschko will meet with foreign ministers in Munich Saturday
Kerry said he will reinforce the need for them to continue to be unified as they press for a reform agenda.
"But we will also say to them: 'If you get that reform agenda, if you are able to secure genuine participation and a genuine ability to bring the country together then we would urge them to engage in that because further standoff and further violence that becomes uncontrollable is not in anybody's interest,' " he said.
Kerry said he has discussed events in Ukraine with his Russian counterpart Sergei Lavrov and has stressed the importance of events there not getting "trapped in some kind of larger ambition for Russia or the United States."
"That's not what this is about," he said. "This is about the freedom of choice for the people of Ukraine and their ability to be able to define their future without coercion from outside forces."
Ukrainians took to the streets in November when Yanukovych backed out of a trade deal with the European Union in favor of closer ties to Russia.
Russian President Vladimir Putin said this week that he wants to wait for a new government in Ukraine before proceeding with a promised $15 billion loan and substantial natural gas discounts.
The United Nations human rights office is calling on Yanukovych to investigate recent reports of deaths, kidnappings and torture during the political unrest. The president announced Thursday that he is going on sick leave for an acute respiratory infection and fever.