President Joe Biden and Vice President Kamala Harris express support despite threat of regional war.

Political leaders in the United States have rallied behind Israel after massive Israeli air strikes in Beirut levelled residential buildings and killed the powerful Hezbollah chief Hassan Nasrallah.

President Joe Biden, Vice President Kamala Harris – both Democrats – and Republican House Speaker Mike Johnson have expressed support for the Friday attack, despite what is expected to be a substantial civilian death toll. Former Republican President Donald Trump does not appear to have commented yet on the killing of Nasrallah.

“Hassan Nasrallah and the terrorist group he led, Hezbollah, were responsible for killing hundreds of Americans over a four-decade reign of terror,” Biden said in a news release on Saturday. “His death from an Israeli air strike is a measure of justice for his many victims, including thousands of Americans, Israelis, and Lebanese civilians.”

The Biden administration has called for a lowering of tensions in the region, but shown little interest in using leverage such as the suspension of weapons sales to restrain Israel following a series of increasingly escalatory attacks in Lebanon in recent weeks. Israel has waved aside calls for a diplomatic agreement and pledged to press forward with continued strikes.

“President Biden and I do not want to see conflict in the Middle East escalate into a broader regional war,” Vice President Kamala Harris, who is the Democratic candidate for president, said in a statement on Saturday. “Diplomacy remains the best path forward to protect civilians and achieve lasting stability in the region.”

Israeli attacks inside Lebanon have killed at least 1,030 people since September 16, including 56 women and 87 children. A final death toll from the massive Israeli strikes that killed Nasrallah and destroyed several large residential buildings on Friday is not yet known, as rescue workers try to find bodies in the rubble.

The killing of Nasrallah, which follows the killing of a series of senior Hezbollah officials by Israel in recent weeks, is a body blow to the Lebanese group and a network of Iran-backed groups across the region. It remains unclear what response the group and its allies in the region, such as Iran-backed militias in Iraq and the Houthis in Yemen, will pursue.

US Defense Secretary Lloyd Austin told Israeli counterpart Yoav Gallant that the US “remains postured to protect US forces and facilities in the region and committed to the defence of Israel” in a phone call on Friday.

The Biden administration has been criticised by activists and analysts who say that his unconditional support for Israel has resulted in a trend of perpetual escalation and Israeli attacks that include large civilian death tolls and violations of international law.

While Trump has yet to comment on the killing of Nasrallah, conservative lawmakers have rejected the Biden administration’s call for a ceasefire and urged stronger support for Israel’s campaigns in Lebanon and Gaza.

“We call on the Biden-Harris Administration to end its counter-productive calls for a cease-fire and its ongoing diplomatic pressure campaign against Israel,” Republican House Speaker Mike Johnson said in a statement on Saturday.