The text of the message is as follows:

In the Name of God
The tragic incident of the crash of a commercial plane which led to the deaths of several of our beloved compatriots filled our hearts with grief and regret. I, hereby, express my deep sorrow and sincere sympathy to their bereaved families and ask God Almighty for great patience and high reward for them and divine mercy and blessing for the deceased. Relevant authorities must summon all their efforts and cooperation for necessary measures in that regard and make arrangements to pay tribute to, and hold a funeral for them.  

Seyyed Ali Khamenei 
February 19, 2018