MOSCOW (Reuters) - Russia's Defense Ministry said on Thursday the United States was using "a verbal smokescreen" to hide its reluctance to fulfill its part of a ceasefire agreement on Syria, including separation of moderate opposition units from terrorist groups.

After the third day of the ceasefire which came into force on Monday evening, only Syria's government forces are observing the truce, the ministry said in a statement.

It said that units of the opposition "controlled by the U.S." have intensified their shelling of civilian residential areas.

(Reporting by Maria Kiselyova; Writing by Dmitry Solovyov; Editing by Maria Kiselyova)