US military's Joint Chiefs of Staff, Michael Mullen, was expected to visit Israel to discuss topics including Iran nuclear issue, the defense department said on Wednesday.

Pentagon spokesman Geoff Morrell confirmed with reporters that Mullen has left on Tuesday for a trip overseas that has been planned for months "to visit counterparts as well as combatant commands," including those in Israel.

"I believe this is a routine opportunity for Chairman Mullen to engage his counterpart in Israel on military-to-military matters," Morrell said, "they will no doubt discuss the threat posed by Iran."

He also noted that although the US government was committed to use diplomacy and international sanctions to solve the Iran nuclear issue, it also retain military strike as an option if it is needed.

Mullen's visit came as speculations rose in the United States that Israel was seeking the US tactic approval for possible attack against Iran nuclear sites.

The US television network CBS reported earlier that Israel does not want to wait until the next US administration to strike Iranian nuclear sites, due to uncertainty of new government's policies on Iran.

However, former Israeli defense chief, Benjamin Ben-Eliezer, has denied the speculation during an interview with Russian reporters, saying "we are not planning any attack against Iran."

Despite being accused by the West of attempting to acquire nuclear weapons, Iran has been defending its rights to develop civilian nuclear programs.

(Xinhua News Agency June 26, 2008)