Russia's President Vladimir Putin will meet his top security officials on Wednesday and address members of government and parliament traveling with him on a trip to the Crimean peninsula a day later, the Kremlin said.
A Russian convoy carrying food, water and other aid set off on Tuesday for eastern Ukraine, where government forces are closing in on pro-Russian rebels, but Kyiv said it would not allow the vehicles to cross onto its territory.
Kyiv and Western governments warned Moscow against any attempt to turn the operation into a military intervention by stealth in a region facing a humanitarian crisis after four months of warfare.
The United States and European Union imposed sanctions on Moscow following its annexation of Crimea from Ukraine in March and over its purported support for pro-Russian rebels in eastern Ukraine.