"I'm sure Israel understands that, I believe he has deleted the tweet in question. It will be up to the UFC as to what they do," Robertson told RNZ.
"But I would certainly be making clear to him, and to anybody actually, that we have to take rape seriously. It's not an issue that anyone should be making jokes or flippant comments about at all."
Rape Prevention Education executive director Debbi Tohill said comments like Adesanya's could normalise threats of sexual violence and with a huge social media following – more than 4.6 million people on Instagram and 860,000 on Twitter – many fans were exposed to the comments.
"People with a large social media following can play a significant role in reducing rates of sexual violence and creating healthy cultures of consent for any sexual activity," Tohill told Stuff.
"Conversely, these kind of comments where rape is used as a threat create a culture where it is acceptable to make sexualised comments with the potential to cause further harm.
"Sportspeople and celebrities can really influence young people, we would like to see this happen in a positive way, not misused and normalising threats of sexual violence."
This is not the first time Adesanya has made an objectionable statement.
Last February, in a press conference ahead of his fight against Yoel Romero, he said he would drop his opponent like the Twin Towers.
"He's human like anyone else … I'll touch him enough times. I'll touch him enough times, and eventually he'll crumble like the Twin Towers."
"Too soon?" Adesanya added after the comment.
He issued an apology following this remark where he said his "brain worked faster than my mouth".
"You speak on the mic enough times and you are bound to miss the mark with some bars. I did on this one and for that I am sorry. I will be more careful in future with my words."
Adesanya is currently undergoing MIQ following his Las Vegas fight on March 7 against Jan Blachowicz and is yet to comment on his most recent remarks.
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