The proposal came in response to the anti-government protests that have swept Iranian cities and towns over the past week, killing about 21 people in the unrest.
Putin met Iranian political leaders in an effort to nurture a warming relationship strengthened since US President Donald Trump threatened to abandon the international nuclear deal with Iran reached in 2015.
Russia and Turkey have a fragile alliance, made worse by the fact that they back opposing sides in the Syrian civil conflict.
There was no immediate claim of responsibility. Officials said they were treating the blast as an act of terrorism, but there was no official confirmation.