WASHINGTON, Sept 28, 2024 (BSS/AFP) - President Joe Biden ordered US forces in the Middle East to be adjusted "as necessary," the White House said Friday, after Israel launched a wave of strikes on Lebanon's capital Beirut targeting Hezbollah's headquarters.

"He has directed the Pentagon to assess and adjust as necessary US force posture in the region to enhance deterrence, ensure force protection, and support the full range of US objectives," the White House said in a statement.

Biden also ordered US embassies in the region to "take all protective measures as appropriate," it said.

The US president, who traveled to his beach house in Delaware on Friday, had been briefed several times by his national security team, the White House added.

Biden had earlier confirmed that "the United States had no knowledge of or participation in the (Israeli) action," adding in remarks to reporters that, "We're gathering information."

Defense Secretary Lloyd Austin also said the US had no advance knowledge, adding that he had spoken by phone with his Israeli counterpart Yoav Gallant "while Israel's operation was already underway".

A US official separately said Israel told Washington "once the operation was already ongoing and they had planes in the air."

Israeli television networks reported that Hezbollah chief Hassan Nasrallah was the target of the strike, though a source close to Hezbollah said he was "fine".