NEW YORK, August 7. /TASS/. The US administration believes that at a certain stage in the negotiations to resolve the conflict in Ukraine, a ceasefire must be declared, US State Secretary Marco Rubio said in an interview with Fox Business.

"At some point, a ceasefire has to be a part of this process, because it is hard to negotiate the details of a final peace agreement while you're shooting at each other," the top diplomat said.

According to him, all sides have a lot of work ahead of them to understand how to end the conflict.