John Negroponte, a veteran diplomat who served under three Republican administrations as well as the Clinton administration, endorsed Hillary Clinton for president on Wednesday.

In a statement provided by the Clinton campaign, Negroponte touted the former secretary of state’s “leadership qualities” in his decision.

“She will bring to the Presidency the skill, experience and wisdom that is needed in a President and Commander in Chief,” he said. “Having myself served in numerous diplomatic and national security positions starting in 1960, I am convinced that Secretary Clinton has the leadership qualities that far and away qualify her best to be our next President.”

The decision comes after Negroponte joined 49 other former security and diplomatic officials from Republican administrations in signing a letter opposing GOP nominee Donald Trump earlier this week.

Negroponte was among the more prominent names on the list, having served as ‎director of national intelligence and deputy secretary of state under President George W. Bush. He also served as deputy national security adviser under President Ronald Reagan, and has held five different ambassadorial posts.

One of those was as ambassador to the Philippines under President Bill Clinton, though he mostly served under Republican administrations. He also was ambassador to Iraq under Bush.

‎The endorsement for the Democratic nominee marks the latest defection for the Republicans, though Trump has played down the intra-party tensions – and described those who signed the 50-official letter as the kind of “insiders” he’s running against.

The Republican nominee said in a statement on that letter that the co-signers “are the ones the American people should look to for answers on why the world is a mess, and we thank them for coming forward so everyone in the country knows who deserves the blame for making the world such a dangerous place.”

The Clinton campaign also announced endorsements Wednesday from former Bush Commerce Secretary Carlos Gutierrez and ex-GOP Rep. Chris Shays, among others.

FoxNews.com’s Judson Berger contributed to this report.