The United States has reportedly said that it is "deeply troubled" by reports of consistent fighting in east Ukraine despite the ceasefire agreement that took effect last week.
While White House spokesman Eric Schultz urged all sides to respect the truce deal, U.S. State Department spokeswoman Jen Psaki warned that there would be "costs" if the violations continued, reported the BBC.
The U.S. has been mulling imposing stricter sanctions on Russia or providing weapons to Ukraine, if diplomacy failed to resolve the Ukraine conflict.
However, Psaki added that the U.S. did not intend to escalate the situation and was only focusing on supporting the implementation of the ceasefire.
Shelling was reported from several parts of east Ukraine on Thursday including, the rebel-held city of Donetsk.
Nato's top military commander, Gen Philip Breedlove, said that the truce deal "existed in name only.
