US unwavering in support of Israel

But in careful statements on the escalating crisis, top Bush administration officials reflected concern that their ally's offensive risked a return to the misery and fractured politics of Lebanon's civil war years.

Analysts warned meanwhile that a further deterioration of the situation could compromise wider US policy goals, as President George W. Bush grapples with raging violence in Iraq, and nuclear and missile showdowns with Iran and North Korea.

Bush, in Germany, spoke up for Israel's right to defend itself after Hezbollah capture of two of its soldiers and killing of eight more sparked its first incursion into Lebanon since it withdrew from the country in 2000.

But he said: "whatever Israel does should not weaken" the government of Lebanese Prime Minister Fuad Siniora.

US officials also took aim at what the United States sees as the two puppet masters of Hezbollah, which the State Department on Thursday branded "terrorist subcontractors for Damascus and Tehran".