President Vladimir Putin has agreed to form a fact-finding mission and a contact group under the auspices of the OSCE to facilitate dialogue on the Crimea.
The proposals were made by German Chancellor Angela Merkel during a telephone conversation with President Putin that took place Sunday, said Georg Streiter, a German government spokesman, the AP reported Sunday.
Fifty-seven countries, including Russia, Ukraine and the U.S., are members of the OSCE, or the Organization for Security and Cooperation in Europe.
During the phone call, Chancellor Merkel also accused Russia of violating the Budapest Memorandum of 1994, in which Russia committed to respect Ukraine's sovereignty, and the Treaty on the Black Sea Fleet from 1997.
Putin replied that Russia's actions to date had been "entirely appropriate," as events in Ukraine had put the lives of Russian citizens and the Russian-speaking population in danger, a statement on the Kremlin website said.
Tensions over the Crimea, which is strategically and historically important for both Russia and Ukraine, have been escalating since Russia began to advance troops toward the region last week.
According to an anonymous Ukrainian military source, two Russian anti-submarine warships were spotted off the Crimean coast on Saturday, breeching Russia's naval lease agreement, The Guardian reported.
Thousands of Russian troops have since moved into the Crimea to secure the region, the BBC reported Monday.
In response to Russia's advancement, Ukraine has mobilized its own troops and turned to NATO for help to ensure its territorial integrity and to protect its citizens.