U.S. defense secretary to visit Israel: officials

As the second cabinet-level representative of the Obama administration to be hosted by Israeli Prime Minister Benjamin Netanyahu, Gates could also lobby for a resolution to the bilateral dispute over the future of West Bank settlements.

Pentagon press secretary Geoff Morrell declined to confirm the trip or what might be on Gates's agenda.

"We don't talk about the secretary's trips, wherever they may be, until such time as we are ready to announce them and nor should anyone else," Morrell said.

"I would not confirm or deny travel plans," he added. "It is not appropriate and it can endanger the secretary and those traveling with him."

Gates has voiced sympathy for Israel's concerns about the possibility of Iran developing nuclear weapons, but has also signaled unwillingness to see the Israelis launch pre-emptive strikes on their arch-foe that could destabilize the region.

The Obama administration has spoken of a need for tougher diplomacy with Tehran, along with reassuring Israel on security.

"We expect Iran to be the main issue. There is obviously a value in a show of Americans and Israelis closing ranks about Iran," said one official about the visit, asking not to be identified because a formal announcement has yet to be made.

The right-wing Netanyahu government says neutralizing the perceived threat from Iran is key to Israeli-Arab peacemaking. But the United States wants parallel progress in bids to set up a Palestinian state that would take in the occupied West Bank.

"This (Gates visit) may be an American attempt to reassure Israel on Iran as part of Washington's pressure for movement on the Palestinian track," the official said.

Iran says its uranium enrichment is aimed at generating electricity but the West suspects is program could be used to develop weapons.

Fiercely anti-Israeli rhetoric from Tehran and support for Islamist guerrilla groups arrayed along the Jewish state's borders have stirred fears of a regional war.

MISSILE Defense

Gates will spend about six hours in Israel, meeting Netanyahu and Defence Minister Ehud Barak, officials said. Barak has been in talks with the United States about boosting missile defenses for Israel, which is believed to have the Middle East's only nuclear arsenal.

Gates is also expected to visit neighboring Jordan.

In a speech last week, Gates described heading off Iran's suspected quest for the bomb as the most difficult challenge facing U.S. national security policymakers.

"If they achieve one, the possibility of a nuclear arms race in the Middle East is very, very real. And if some action is taken to prevent them from getting one, the consequences of that are completely unpredictable, and likely very bad," he said.

"... It's not just the United States that faces this problem. After all, Iran is going to have missiles that can deliver nuclear weapons to people in their region a lot sooner than they're going to have the capability to deliver one to us."

Gates last visited Israel in 2007, while defense secretary under U.S. President George W. Bush. U.S. Secretary of State Hillary Clinton was the first member of President Barack Obama's cabinet to visit Israel last March.

(Additional reporting by Andrew Gray in Washington; Editing by Peter Millership and Sandra Maler)