Arens, an aeronautics engineer, was also known for having played a key role in Israel’s aerospace and military industries, including by pushing for the development of the Lavi Israeli fighter jet.
Netanyahu and Israeli president Reuven Rivlin eulogised the Lithuanian-born, US-raised Arens.
“My wife Sara and I shed bitter tears over the passing of our beloved Moshe Arens,” Netanyahu said in a statement.
He recalled Arens’s terms as ambassador to Washington, foreign minister and defence minister, using his nickname Misha, and said he remained clear-headed even in the last stages of his illness.
“A few weeks ago, I visited Misha at his home,” Netanyahu wrote. “He was as lucid as ever, as sharp as a razor.”
Israeli public radio said Arens was suffering from “a severe sickness,” a common media euphemism for cancer.
Haaretz newspaper said he died in his sleep at his home near Tel Aviv.
The Times of Israel said he was survived by his wife Muriel, four children and nine grandchildren.
“Misha worked his whole life in key positions to ensure Israel’s development and success,” Rivlin said in a statement.
“As a scientist and engineer, as a statesman, as an ambassador and as a manager of the most important industries for Israel’s security.”
– Lithuania to New York –
Arens, of the right-wing Likud party, personally brought Netanyahu into politics in 1982 — hiring the then US furniture salesman as a diplomatic liaison officer in Israel’s Washington embassy.
Two years later Netanyahu, the son of a historian active in Israeli right-wing politics, became Israel’s ambassador to the United Nations.
Arens later backed the younger man’s bid to lead Likud after the party’s 1992 election loss to the Labour Party.
But after Netanyahu won election as prime minister in May 1996, Arens grew increasingly critical of his protege’s style.
Arens was born in Kaunas, Lithuania on December 27, 1925 and in 1939 emigrated with his family to the United States, where he grew up in New York City.
He studied mechanical engineering at the Massachusetts Institute of Technology (MIT), which Netanyahu also attended later.
His studies were interrupted in August 1944, when he enlisted in the US Army Corps of Engineers.
He served for two years, reaching the rank of sergeant first class.
After discharge he returned to MIT, receiving a degree in mechanical engineering, then immigrated to Israel on the state’s founding in 1948.
He later went back to the US to take a masters degree in aeronautical engineering at the California Institute of Technology.
He would become vice-president of engineering at Israel Aircraft Industries, where he managed aircraft and missile development projects.
Arens entered parliament in 1973, remaining there until he retired from politics in 2003, except for a year as Israel’s ambassador to the US in 1982-1983.
A hawk, he voted against the 1978 Camp David accords with Egypt, Israel’s first peace agreement with an Arab country.