In a reflection of election-season sensitivity over the US-Israel security relationship, the US Department of Defense on Sunday dismissed the claims of an unnamed senior Israeli military official who charged that a scaling down of the joint October missile defense exercise “Austere Challenge 12″ signaled mistrust between the US and Israel.

The down scale will reportedly affect the number of US troops participating in the exercise – possibly as few as 1,200 instead of the originally planned 5,000 – and will likely see just a single Aegis Ballistic Missile Defense warship arriving in Israel instead of two.

According to Time magazine, the senior Israeli official said, “Basically, what the Americans are saying is, ‘We don’t trust you.’”

But on Sunday, Department of Defense officials suggested “Israeli commentators” quoted by the press “are not in the know with [Israel’s] Prime Minister’s Office, the Ministry of Defense or the IDF.”

According to a statement released by DoD spokesman George Little, the scaling down of troops involved in the exercise was due to repeated Israeli requests to postpone the exercise till October.

Combined with the announcement last week of a massive Iranian missile defense exercise in that same month and widespread speculation that Israeli Prime Minister Benjamin Netanyahu may be planning to strike Iran’s nuclear program in the weeks before the November 6 US elections, the timing of the Israeli request has raised eyebrows.

According to Little’s statement, “The exercise was originally scheduled for May, however at the request of the Israeli Ministry of Defense and Israeli Defense Forces, the exercise was moved to late fall of this year.

“When the exercise was moved, the United States notified Israel that due to concurrent operations, the United States would provide a smaller number of personnel and equipment than originally planned. Israel reiterated its request to postpone until late fall.”

The DoD statement went on to note that “Austere Challenge 12 remains the largest ever ballistic missile defense exercise between our nations and a significant increase from the previous event in 2009. The exercise has not changed in scope and will include the same types of systems as planned. All deployed systems will be fully operational with associated operators.”

In a likely nod to election rhetoric over White House support for Israel’s security, the DoD statement concluded by noting that, “as Israel Minister of Defense Ehud Barak has repeatedly said, the US-Israel defense relationship is stronger than it has ever been. The United States agrees. Austere Challenge is a tangible sign of our mutual trust and our shared commitment to the defense of our nations.”