EU foreign ministers postponed new sanctions against Russia for a week to boost the chances of success at a four-way Ukraine peace summit Wednesday, EU foreign affairs head Federica Mogherini said.
"In order to give space for our diplomatic efforts with the maximum chance of success we decided to put implementation on hold until Monday," Mogherini told a news conference after a meeting in Brussels on Monday.
"We believe it is our duty to gives this attempt a chance," Mogherini added, after the ministers from the 28 European Union nations discussed the latest efforts to end a conflict which has claimed some 5,400 lives.
EU foreign ministers agreed last month 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.
Brussels first imposed targeted sanctions on individuals after Russia's annexation of Crimea in March 2014 but adopted tougher economic sanctions after the shooting down of Malaysia Airlines flight MH17 over Ukraine in July.
Mogherini said the EU would review the situation, taking into account the Minsk summit outcome and developments on the ground.
"We have been consistent in our decisions and united; we count on continuing to do so for the future," she said.
EU leaders are due to meet informally on Thursday when Ukraine will once again dominate proceedings.
German Foreign Frank-Walter Steinmeier warned separately that the discussion of arming Kiev -- an option attracting increasing support in Washington but bluntly opposed in Berlin -- would inevitably arise in Europe if the talks failed.
"If current efforts do not succeed the conflict will escalate militarily to the next level and then the question of weapons deliveries will certainly be discussed here in Europe as well," he said.
Russian President Vladimir Putin hosted German Chancellor Angela Merkel and French President Francois Hollande for late-night talks on Friday and agreed to meet, along with Ukraine President Petro Poroshenko, in the Belarus capital Minsk on Wednesday.
Officials were hammering out the summit details Monday as fresh fighting left more dead and Kiev charged that 1,500 Russian troops and convoys of military hardware had crossed into the country over the weekend.
The warring parties met in Minsk in September when they agreed a ceasefire and peace plan but it never took hold and Russian-backed rebels ditched it completely last month as they launched new attacks on Ukraine government forces.
These Minsk accords are expected to form the basis of any new ceasefire but many issues remain unresolved such as withdrawal from the line of contact now that the rebels have captured so much new territory.