(Adds Lavrov comment, detail, context)
VIENNA, March 21 (Reuters) - The OSCE is to hold an extraordinary meeting on Friday evening and diplomats said the European rights and security body could finally reach a unanimous agreement to send a monitoring mission to Ukraine.
Asked if agreement had been reached in principle among the 57 states that make up the Organisation for Security and Cooperation in Europe, one Western diplomat said: "It seems so."
The meeting was scheduled to start at 1830 GMT at the OSCE's Vienna headquarters, officials said.
Ukraine, locked in a confrontation with its former Soviet overlord Russia over Moscow's annexation of its Crimean peninsula, wants OSCE monitors to be deployed on its territory, as do Western countries.
However, attempts to reach agreement have so far failed due to what Western diplomats described as Russian objections to the mission's mandate. Russia, Ukraine and the United States are all members of the OSCE.
However, on Friday, Russian Foreign Minister Sergei Lavrov said a deal was close, telling President Vladimir Putin in televised remarks: "We have already practically agreed a draft decision.
He said observers would be sent to western and central regions in addition to the largely Russian-speaking east and southeast.
Russia has accused Ukrainian nationalists of intimidating Ukraine's large minority of Russian-speakers and ethnic Russians, many of them in the east and southeast, since the pro-Russian president, Viktor Yanukovich, was forced out last month. Moscow has reserved the right to send troops to Ukraine to defend them.
Lavrov earlier criticised Western calls for OSCE observers to be sent to Crimea, which Russia has annexed. Military monitors from individual OSCE member states made several unsuccessful attempts to enter the territory but were turned back and, on one occasion, warning shots were fired.
Diplomats have said the mission now under discussion would consist of more than 100 observers and would be sent to various places in Ukraine soon after a decision by OSCE ambassadors.
Their task would be to monitor human rights, security and other issues, a role similar to the one the OSCE played in the countries that emerged from the bloody collapse of Yugoslavia in the 1990s. Diplomats say its work has been hobbled in recent years by a resurgence of East-West tension. (Reporting by Fredrik Dahl and Derek Brooks; Editing by Kevin Liffey)