WASHINGTON -- U.S. Sen. Robert Menendez, the former chairman of the Senate Foreign Relations Committee, endorsed Democratic front-runner Hillary Clinton for president on Wednesday, calling presumptive Republican nominee Donald Trump "an unmitigated disaster."

Menendez (D-N.J.) backed Clinton over fellow U.S. Sen. Bernie Sanders of Vermont, who also is seeking the Democratic presidential nomination. In an article published on PolitickerNJ, Menendez said Clinton was the only candidate with "the experience, the interest, and the demeanor to lead and protect our nation."

His endorsement comes two weeks before New Jersey's presidential primary on June 7.

Menendez had withheld his backing until now, even as most of New Jersey's other Democratic federal lawmakers, including fellow Democratic Sen. Cory Booker, pitched their tents in Clinton's camp.

Though he lined up with Trump and opposed President Barack Obama's deal to curb Iran's nuclear program for more than a decade in exchange for relaxing economic sanctions, Menendez said it was not a difficult choice to support Clinton.

Trump's "foreign policy views -- to the extent he has them -- are often invented on the spot," Menendez wrote. "Quite simply, he has shown no regard for the norms and necessities that so much of our modern diplomatic and security efforts depend upon."

A regular speaker at the American Israel Public Affairs Committee's legislative conference in Washington, Menendez praised Clinton's support for the Jewish state.

"As someone who has worked closely with Hillary, I've seen her commitment to defending Israel's national security interests first hand," Menendez said.

Trump had said he would be neutral in the Middle East, though he insisted his vow of neutrality meant only that he wanted to be seen as an honest broker by both sides. He was booed at the Republican Jewish Coalition forum in December when he refused to declare Jerusalem the undivided capital of Israel, saying he didn't want to prejudge negotiations.

At the AIPAC conference in March, though, he made it clear where he stood. "I am a newcomer to politics but not to backing the Jewish state," he said.

Menendez said Clinton supports a two-state solution and has the experience and know-how to work toward that goal, Menendez said.

"As president, she will continue working toward the goal of providing Israelis with a secure homeland for the Jewish people and allowing Palestinians to peacefully govern themselves in their own state," he said.

Menendez lost the committee chairmanship with the Republicans took control of the Senate in 2015. He temporarily relinquished his position as the panel's top Democrat after he was indicted last year on federal corruption charges. He is awaiting a U.S. appeals court ruling on his contention that the charges should be dismissed because they were legislative actions protected under the Constitution.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook