Ukraine, Russia, the United States, and the European Union have announced agreement on measures aimed at defusing the crisis in Ukraine.
After daylong talks April 17 in Geneva, the parties called on all illegal armed groups across Ukraine to disband, to stop occupying public buildings, and to refrain from violence.
Officials said Ukrainian authorities have also agreed to grant amnesty to protesters who illegally occupied property during Ukraine’s unrest, excluding those found guilty of capital offenses.
The four parties also agreed to the deployment of an OSCE mission to oversee de-escalation in Ukraine.
The parties said the United States, EU, and Russia were committed to support the mission, including by providing monitors.
U.S. President Barack Obama expressed cautious optimism over the deal.
But Obama said if Russia fails to live up to its end of the bargain the United States and its allies are ready to impose fresh sanctions.
The White House said Obama and German Chancellor Angela Merkel had agreed during a telephone call on April 17 that they are ready to punish Russia further if it does not de-escalate the situation in eastern Ukraine "in short order."
Russian Foreign Minister Sergei Lavrov emphasized the call to disband illegal armed groups applied to all groups across Ukraine, including ones that support the new authorities in Kyiv.
In particular, Lavrov said the Ukrainian nationalist group Right Sector, which played a key role in the protests that ousted pro-Russian President Viktor Yanukovych in February, has so far refused to disarm.
Lavrov also stressed Moscow's position that Kyiv should negotiate with representatives of all regions of Ukraine on constitutional reforms.
Lavrov said Russia has "no wish to bring our troops to Ukraine."
'Words On Paper'
The four parties also condemned all activity in Ukraine seeking to discriminate on the basis of ethnicity or religion.
Kerry condemned a reported anti-Jewish incident in eastern Ukraine, and a threat to the Russian Orthodox Church.
Kerry said that if the four-party agreement collapses, the United States will have no choice but to impose further measures aimed at punishing Russia.
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Kerry said the four parties agreed they could not leave Geneva with the idea that "words on paper" represented progress. He said all agreements reached in Geneva must be translated into actions.
Kerry said there was no progress on the issue of Russia withdrawing some of its military units from the Ukrainian border region.
Kerry said Russia had pledged to pull back one battalion. But he did not confirm this has happened yet.
EU foreign policy chief Catherine Ashton, who appeared at the press conference with Kerry, affirmed that the EU remains committed to Ukraine's sovereignty, unity, and territorial integrity.
Ashton also announced there would be a three-way meeting involving EU, Russian, and Ukrainian officials to discuss supplies of Russian gas reaching Europe through Ukraine.
Moscow has threatened to suspend supplies of gas to Ukraine due to Kyiv's multi-billion dollar bill, raising fears in the EU that gas supplies could be reduced or cut off to Europe.