BRUSSELS — The European Union on Monday shied away from slapping new economic sanctions on Russia right away over its actions in eastern Ukraine. Instead, the 28-nation bloc said the punitive measures will come into force “in the next few days” depending on how well the cease-fire agreement in eastern Ukraine will be upheld.

European Council President Herman Van Rompuy said in a statement delaying the sanctions would leave time for “an assessment of the implementation of the cease-fire agreement and the peace plan.”

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

Ukraine, Russia and the Kremlin-backed separatists agreed Friday to an immediate cease-fire and an exchange of prisoners. While the truce appeared to hold on Monday, the agreement seemed fragile over the weekend when occasional fighting occurred.