The EU has agreed to postpone new sanctions against Russia to give time to see if a four-way Ukraine peace summit makes progress, French Foreign Minister Laurent Fabius says.

"The principle of the sanctions will be kept, but their implementation will depend on the situation on the ground," Fabius told reporters in Brussels on Sunday.

"We will assess the situation again next Monday."

Foreign ministers from the 28-nation European Union had agreed on January 29 to add 19 people, including five Russians, to a list of those facing travel bans and asset freezes after an upsurge in fighting in eastern Ukraine.

They were meant to formally sign off on the decision in Brussels on Monday, but decided to compromise pending the outcome of Wednesday's crunch summit of the French, German, Russian and Ukraine leaders in the Belarussian capital Minsk.

The Minsk meeting was agreed after Russian President Vladimir Putin hosted German Chancellor Angela Merkel and French President Francois Hollande for late-night talks in the Kremlin on Friday.

Fabius said the peace initiative showed that "things have begun to move", but added that any deal should be based on a largely defunct pact signed between Kiev and Kremlin-backed separatists in Minsk in September.