U.S. Defense Secretary Robert Gates arrived Thursday in Israel, one day after an eruption in violence that has complicated his plans to urge progress in the peace process.

The latest spike in attacks began Wednesday with a bus-stop bombing in Jerusalem, followed by Israeli strikes on Hamas targets in Gaza. The events have heightened tensions and added to Israel's anxiety over the wave of rebellion in the region.

Gates is urging Israeli leaders to push forward on the peace talks with Palestinians as a way to get ahead of what one senior defense official called the populist wave crashing across the region. The official said Gates will make the argument that the best way to do that is to negotiate peace, removing that issue from the discourse as old regimes fall and new governments are formed.

The official, who spoke on condition of anonymity to discuss internal deliberations ahead of the meetings, said the unrest in Egypt and other nearby nations has rattled the pillars of Israeli security, which include peace agreements with Egypt and Jordan.

There are worries, the official said, about the new government forming in Egypt, and whether the eventual leaders would be as committed to peace with Israel as deposed President Hosni Mubarak was. There are also concerns that the unrest in the Arab world could undermine Jordan's stability.

Gates flew Thursday to Tel Aviv from Cairo, where he urged Egyptian authorities to give new political organizations time to organize as the country begins to take tentative steps toward democracy. He also met with military leader Field Marshal Mohamed Hussein Tantawi, and praised the Egyptian military for protecting protesters during the rallies that led to Mubarak's ouster.

Gates is scheduled to meet Thursday with Israeli Defense Minister Ehud Barak and President Shimon Peres, and Friday with Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas.