Russian President Vladimir Putin called President Obama to "discuss the U.S. proposal for a diplomatic resolution to the crisis in Ukraine," the White House said on Friday.

Obama, the White House said, suggested Russia "put a concrete response in writing" to a proposal delivered by Secretary of State John Kerry to Foreign Minister Sergei Lavrov during their meeting at the Hague this week.

The presidents agreed that Kerry and Lavrov should meet "to discuss next steps."

In a readout of the call, the White House said Obama told Putin that Ukraine has taken a restrained position toward Russia, and he urged Russia to support the country's move toward democratic elections and constitutional reform.

The two countries have been at an impasse since Russia annexed Crimea, a peninsula in the southern part of Ukraine with historic ties to Russia. Obama has tried to rally European support for sanctions against Russia over the crisis.

"President Obama underscored to President Putin that the United States continues to support a diplomatic path in close consultation with the Government of Ukraine and in support of the Ukrainian people with the aim of de-escalation of the crisis," the White House said. "President Obama made clear that this remains possible only if Russia pulls back its troops and does not take any steps to further violate Ukraine's territorial integrity and sovereignty."

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