A Pentagon spokesman, Navy Rear Adm. John Kirby, said Hagel discussed Ukraine with Defense Minister Sergei Shoigu in an hour-long phone conversation.
"Secretary Hagel appreciated Minister Shoigu's time and the minister's assurance that the troops he has arrayed along the border are there to conduct exercises only, that they had no intention of crossing the border into Ukraine and that they would take no aggressive action," Kirby said.
Asked whether Hagel accepted that explanation, Kirby said Hagel expects that Shoigu "will meet his word."
When Hagel asked how long the Russian military training exercise would last, Shoigu said he could offer "no firm timetable," Kirby said.
Kirby said Hagel initiated the call, having in mind Russia's moves against Crimea.
Hagel asserted to his Russian counterpart that because Russian forces are in control of the Crimean Peninsula, they bear responsibility for what happens there, Kirby said.
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