Russia says it has no plans to punish Kosovo with sanctions after it makes a declaration of independence.
The EU mission is likely to last a number of years
But Foreign Minister Sergei Lavrov told reporters secession would be a mistake and everything possible should be done to "prevent negative developments".
Speaking after talks with EU officials, Mr Lavrov accused foreign powers of pushing Kosovo towards independence.
The breakaway Serbian province is expected to make a declaration soon, possibly at the weekend.
EU External Relations Commissioner Benita Ferrero-Waldner said Kosovo needed stability.
"We hope we will be able to convince Russia that the [current] situation is unsustainable," she said.
A civilian police and justice mission for Kosovo is expected to be given the go-ahead by EU member states by the end of the week.
A senior official told the BBC's Oana Lungescu in Brussels that deployment of the 1,800 staff would be staggered over four months.
By early June, 1,500 police officers including special anti-riot units and 250 judges, prosecutors and customs officials would be in place to maintain stability in the self-proclaimed state.
The police and judges are expected to come from Germany and Italy as well as other countries, including the United States, Turkey, Croatia, Norway and Switzerland.
UN Security Council
The EU is basing its mission on UN Security Council resolution 1244 which gave Kosovo "substantial autonomy" and put in place a UN mission and a Nato peacekeeping force.
Russia and Serbia dispute the legality of the new mission and have called a meeting of the UN Security Council for Thursday.
But Mr Lavrov told reporters he did not feel great optimism in the session.