Ukrainian authorities reportedly say Russia has used about 60 North Korean ballistic missiles to attack Ukraine.

According to the local media outlet RBC-Ukraine on Monday local time, Andriy Cherniak of Ukraine’s military spy agency came up with the number. 

Earlier reports cited Ukrainian authorities as saying North Korea had provided Russia with over 100 KN-23 and KN-24 short-range ballistic missiles, which Russia began using at the end of last year.

Speaking on a local radio program, Cherniak also said Russia may have obtained millions of artillery shells from North Korea.

He said while Russia has its own military supplies, it increasingly relies on North Korean ammunition as the war drags on.