Eight years ago, New Zealand offered to resettle 150 refugees a year from Australia's offshore detention system.
Williams is urging Morrison to finally accept the offer.
"I think 250 people or close to, have been left in Papua New Guinea and in Nauru that can be brought to have a better life.
"They've been stuck for the last eight years. We can't even do it for two weeks in quarantine, imagine doing it for eight years."
He told Morning Report that New Zealand needed to understand the meaning of refugees.