National security adviser Jake Sullivan said on Thursday the U.S. has not determined that Russia has decided to take a military path forward in Ukraine, and said the U.S. is prepared to continue with diplomacy to advance stability in that region.

Sullivan also told reporters that no dates had been set for further talks with Russia.

"Basically we are still at a moment where we believe a path of diplomacy can operate in a way that vindicates and reflects our interests and principles," he told a news conference.

(Reporting by Trevor Hunnicutt; Writing by Chris Gallagher; Editing by Leslie Adler)