A statement from Israeli Defence Minister Benny Gantz said Esper was expected in Tel Aviv at 13:15 pm (1115 GMT) for a two-hour visit that included meetings with senior Israeli military officials.

But the source, who requested anonymity, said Gantz and Esper would build on discussions held in Washington last week on "making progress towards upgrading Israel's qualitative military edge" following "developments in the region".

Last week, Israel said it would not oppose US sales of F-35 fighter jets to the United Arab Emirates after the UAE became only the third Arab state to normalise ties with Israel.

That broke with years of Israeli policy opposing the sale of the fighter planes to any US allies in the region including Egypt and Jordan, both of which have peace treaties with Israel.

Israeli Prime Minister and Gantz said in a joint statement last week that Washington was in the process "of upgrading Israel's military capability and maintaining Israel's qualitative military edge."

Esper's stop in Israel, less than a week before a US presidential election, comes after he held two days of meetings in India.