US Republican Senator Susan Collins speaks during a news conference on Capitol Hill, on June 21, 2016 in Washington, DC. (AFP photo)
US Republican Senator Susan Collins says her party's presidential nominee Donald Trump, if elected, will make the world "more dangerous".
"Donald Trump, in my judgment, would make a perilous world even more dangerous," Collins said in an interview with CNN on Tuesday.
"I worry that his tendency to lash out and his ill-informed comments would cause dangerous events to escalate and possibly spin out of control at a time when our world is beset with conflicts. That is a real problem," she added.
The senator from Maine had already expressed her reluctance to endorse Trump as long as the GOP nominee did not change his inflammatory rhetoric and policies.
Donald Trump addresses the audience during a campaign event in Wilmington, North Carolina, on August 9, 2016. (AFP photo)
During the interview, Collins said she believes Trump "simply does not have the restraint and the consideration and the judgement and the knowledge to handle those dangerous events with which presidents are inevitably confronted."
A handful of other Republican senators have joined Collins in not voting for the New York businessman for president and several of others have voiced their resistance to the notion.
Collins also said she would not vote for Democratic presidential nominee Hillary Clinton.
"I truly don't know. I have a lot of concerns about Hillary Clinton, and I am not going to support her," Collins said when asked who she would vote for. "I may well end up writing in a name for president, something I have never done before."
The real estate mogul's campaign has been marred by his disparaging remarks against minorities in the US. His comments include a call to ban all Muslims from coming to America as well as forced deportation of Mexican migrants.
He has also sought for a database to track Muslims across the United States and said that the US would have "absolutely no choice" but to close down mosques.
Trump’s proposal has been condemned by Muslim and human rights groups as well as his Democratic rivals and many of his Republican proponents who describe the proposal as divisive, counterproductive and contrary to American values.