The United States takes Russian President Vladimir Putin's nuclear threats seriously but does not presently see indications of the use of nuclear weapons, U.S. national security adviser Jake Sullivan said on Friday.
Sullivan told reporters at the White House the United States was taking the risk very seriously and communicating directly with Russia about the issue, including about decisive responses the United States would take if Moscow went down "that dark road."
(Reporting by Steve Holland and Jeff Mason; Editing by Leslie Adler)
