SSH - Unable to negotiate - diffie-hellman

I am trying to SSH to my router on Eve-en (VIOS) and I receive the below error:
Unable to negotiate with 192.168.40.140 port 22: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1

I tried to add the key in known_hosts but it didn't solve my problem.
Could anyone elaborate on this case?