In a visit likely to fuel speculation about possible Israeli military action against Iran, Chairman of the US Joint Chiefs of Staff Admiral Michael Mullen will touch down briefly in Israel at the end of the week for talks with IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi, top defense officials told The Jerusalem Post on Monday. A few weeks after Mullen's visit, Ashkenazi will fly to Washington DC for several days on his first visit to the US as chief of staff. Mullen's visit to Israel is part of a European tour. Officials said the US military chief had a free day in his itinerary and instead of remaining in Europe decided to fly to Israel. The visit comes just weeks after the Israel Air Force reportedly flew 100 fighter jets 1,500 kilometers across the Mediterranean in an unprecedented exercise widely reported as a "dress rehearsal" for an attack against Iran. Mullen last visited Israel in December - the first visit from a US chairman of the joint chiefs of staff in over a decade. A second visit in such a short time, defense officials said Monday, was a demonstration of the close relationship Mullen had forged with Ashkenazi and the gravity with which he viewed the threats Israel was currently facing. US Chief of Naval Operations Admiral Gary Roughead, who is currently in Israel on an official visit, told the Post Monday that the US military knew about the reported massive aerial exercise. "There are many ways that we receive information," he said, adding that questions about the reported exercise's intent should be directed to the IAF. Referring to an incident in January when Iranian Revolutionary Guard gunboats provocatively approached US ships in the Strait of Hormuz, Roughead said "In recent months, we have had a couple of encounters with IRG naval units that were irresponsible, provocative and not helpful to the stability and security in the Gulf... I do believe that unless the IRG begins to behave in a more responsible manner that encounters like that will perhaps continue to occur." During his visit, Roughead met with Ashkenazi, Defense Minister Ehud Barak and Israel Navy commander Admiral Eliezer Marom, with whom he discussed the need for continued cooperation between the US and Israeli navies. Roughead and his Israeli counterparts also discussed missile defense systems - particularly the US Navy's Aegis system, which was successfully tested earlier this month. Defense officials have said that in the event of a conflict with Iran, it was possible the US would deploy an Aegis system off Israel's coast to provide another layer of defense against Iranian ballistic missiles. "I believe that the proliferation of ballistic missiles is something that will continue to occur [and] I believe that ballistic missiles in the future will become weapons of intimidation and blackmail," Roughead said.