The new measures include restrictions on large Russian state-owned oil companies raising money on European financial markets.

However, the new measures will come into effect "in the next few days", not on Tuesday as some had expected.

Russia denies accusations by Ukraine and the West that it has been sending troops to help pro-Russian militants.

EU Council President Herman van Rompuy said the measures were aimed at "promoting a change of course in Russia's actions destabilizing eastern Ukraine".

But the 28-member bloc is being deliberately vague about when they will come into force, to allow time to assess the implementation of a ceasefire agreed on Friday.

"Depending on the situation on the ground, the EU stands ready to review the agreed sanctions in whole or in part," van Rompuy said.

The ceasefire appears to be holding, although the head of the Organization for Security and Cooperation in Europe (OSCE), which brokered the deal, described it on Monday as "shaky".

Before the truce came into place, pro-Russian separatists made big gains in eastern Ukraine and seized territory a few miles outside the strategic south-eastern port city of Mariupol.

The gas sector is not affected by the latest sanctions. However, major state-owned oil firms are included, such as Rosneft, which is already targeted by US measures.

Russia has warned that it could block international flights through its airspace if the EU goes ahead with new measures.

BA/BA