The first planeload of humanitarian aid is due to take off for Japan from Moscow on Tuesday evening, a spokeswoman for the Russian Emergency Situations Ministry Irina Andrianova said.
The plane has about 9,000 blankets aboard.
The 9-magnitude earthquake hit the north-eastern Japan on the 11th of March, causing a 10-m high tsunami wave.
The death toll is feared to exceed 10,000 people in the Miyagi prefecture alone, though the number of officially confirmed casualties now stands at 3,375.
Tens of thousands are still missing, while hundreds of thousands were left homeless.
Russia has joined rescue operation in the quake-devastated area.