BERLIN (AP) — U.S. Secretary John Kerry said Friday that overtures by Ukraine's embattled president to the country's political opposition have not been enough to resolve the crisis there.

Kerry made the comments during a news conference with German Foreign Minister Frank-Walter Steinmeier at a stopover in Berlin en route to a regional security conference in Munich.

The visit to the German capital appeared aimed at improving relations with Germany that were severely strained by allegations of U.S. spying, including tapping Chancellor Angela Merkel's cell phone.

Kerry spoke a day after President Viktor Yanukovych announced he was taking an indefinite sick leave, prompting a guessing game among Ukrainians whether he was really ill or deliberately leaving the spotlight — either ahead of a crackdown or to step aside.

"The offers of President Yanukovych 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 can legitimately come to the table," Kerry said.

But he added that if the government presents a reform agenda offering "genuine participation" then the opposition should seize the opportunity "because further violence that goes out of control is not in anybody's interest."

Kerry said he would reach out to Russia to convince Moscow that an agreement in Ukraine is in its interest.