Donald Trump is "unqualified and unfit to be President," said a former Reagan administration official as he endorsed Hillary Clinton on Friday.

Come November, Robert Tuttle, the former director of presidential personnel in Reagan's administration and an ambassador to the United Kingdom under George W. Bush, will cast his first ballot for a Democratic presidential candidate.

The nominee of the Republican party "has done nothing in his career to demonstrate that he is competent to be President," Tuttle said in a statement issued by the Clinton campaign.

"He has made repeated misstatements and inaccurate statements. He has insulted minorities, women, a war hero and Gold Star parents. He is unqualified and unfit to be President," he said of Trump.

"I have never voted for a Democrat but I will vote for Secretary Clinton," Tuttle declared.

The longtime Republican joins a growing list of GOP leaders who have defected to support the Democratic nominee for president. Like Tuttle, many have said Trump's lack of governing experience, rhetoric and temperament should disqualify him from serving as commander in chief.

"Tuttle is the latest Republican leader to step forward, put party ahead of country in this election, and endorse Hillary Clinton for President," the Clinton campaign said in response to his endorsement.

The Clinton campaign on Wednesday announced its plans to boost outreach to Republicans and right-leaning independents who are dissatisfied with their own presidential nominee through a new initiative called "Together for America."