International monitors will be sent to Ukraine, after Russian diplomats dropped their objections.
European security organisation, the OSCE, will send advance teams within 24 hours to areas including the violence-hit south-eastern areas.
But the 100-strong monitoring team is not expected to go to Crimea, which was taken over by Russia last month.
Russian leader Vladimir Putin signed a law formalising Crimea’s annexation on Friday, despite EU and US sanctions.
The 57-member Organisation for Security and Co-operation in Europe reached a deal on Friday evening.