Russia's defence secretary has assured his US counterpart that there are no military personnel in its controversial aid convoy for Ukraine, the US says.
It said Sergey Shoygu told Chuck Hagel the convoy was not being used as a pretext to intervene further.
The convoy, which aims to aid eastern Ukrainian cities held by pro-Russian rebels, is stalled at the border.
Earlier Russia denied Ukraine's claims that a column of Russian armoured vehicles had crossed the border.
The Pentagon said Hagel had sought clarification on the convoy.