Bill Weld, Libertarian vice-presidential nominee hopeful and former Republican governor of Massachusetts has reiterated his view that presumptive GOP nominee Donald Trump’s immigration plan is comparable to the Holocaust.

“I can hear the glass crunching on Kristallnacht in the ghettos of Warsaw and Vienna when I hear that,” Weld told the New York Times Thursday when asked about Trump’s plan to deport the 11 million immigrants living illegally in the US. He reiterated his opinion over the weekend.

“My Kristallnacht analogy does evoke the Nazi period in Germany. And that’s what I’m worried about: a slippery slope,” he added.

Kristallnacht or The Night of Broken Glass was a Nazi rampage which resulted in the destruction of thousands of Jewish homes, businesses and synagogues and at least 91 deaths.

It got its name from the shards of broken glass that littered streets in its aftermath and is considered to be the beginning of the ‘Final Solution’ which culminated in the Holocaust, during which some six million Jews were exterminated.

When pushed on whether he believed Trump was a Nazi or fascist he said no.

“I wouldn’t call Mr. Trump either a fascist or a Nazi, I’m just saying, we got to watch it when we get exclusionary about people on account of their status as a member of a group.”

Weld told CNN Sunday that he stands by his remarks and does not believe it to have been too strong a statement.

“No, I don't think so. I served five years on the US Holocaust Commission by appointment of President George W. Bush ... I'm absolutely certain that, as we said in those years, if we don't remember, we absolutely will forget.”

“And you got to forget a lot of things to think it's a good idea to round up and deport 11 million people living peaceably, most of them working in America, in the middle of the night,” he added. “No, not the United States. China, maybe. Not the United States.”

Former prosecutor Weld was chosen by former New Mexico Republican governor Gary Johnson as his running mate earlier this month.

READ MORE: Libertarian Gary Johnson picks former Massachusetts governor as running mate

Johnson, who is seeking the Libertarian Party's presidential nomination said on Saturday that he would not have made the Holocaust reference but defended his running mate’s comments.

“What are we going to do? Are we going to go in these homes and take these people out of their homes? Come on. He made that reference. I don't make that reference, but it's crazy. It's off the charts,” Johnson told CNN.