U.S. Vice President Joe Biden has spoken by phone with Ukrainian President Petro Poroshenko about the situation in eastern Ukraine.
According to the White House, Poroshenko informed Biden on February 28 of continued shelling around Donetsk and Mariupol by Russian-backed separatists in violation of Minsk cease-fire agreement.
The two also discussed the inability of the Organization for Security and Cooperation in Europe (OSCE) to verify whether Russian heavy weapons have been pulled back from the front lines, it said.
Biden praised the Ukrainian government's plan to pass reform legislation, recommended by the International Monetary Fund, to stabilize the economy, the White House said in a statement.
The Ukrainian military said the truce had been most fully observed overnight around the rebel-controlled city of Luhansk and near government-held Mariupol on the Sea of Azov.
Despite the lull in fighting, a Ukrainian journalist was killed by shelling in eastern Ukraine on February 28.