As Israel weighs its options after its arch-foe Iran launched its largest ever assault on Tuesday, Biden was asked on Thursday whether he would support Israel striking Iran's oil facilities.
"We're discussing that," Biden told reporters.
His comments contributed to a surge in global oil prices, and rising Middle East tensions have made traders worry about potential supply disruptions.
"There is nothing going to happen today," Biden said. On Wednesday, the president said he would not support any Israeli strike on Iran's nuclear sites.
Israel's UN Ambassador Danny Danon told CNN on Thursday his country has "a lot of options" for retaliation and would show Tehran its strength "soon".
A US official said Washington does not believe Israel has decided yet how to respond to Iran.
Israel is weighing its options after arch-foe Iran launched its biggest ever attack on Tuesday. (AP PHOTO)
Beirut's southern suburb of Dahiye, a stronghold of the Iran-backed armed group Hezbollah, came under renewed strikes near midnight on Thursday after Israel ordered people to leave their homes in parts of the district, residents and security sources said.
The air raids targeted Hezbollah official Hashem Safieddine, rumoured successor to assassinated Hezbollah leader Hassan Nasrallah, in an underground bunker, Axios reporter Barak Ravid said on X, citing three Israeli officials. Safieddine's fate was not clear, he said.
Israel's military declined comment.
Israeli Prime Minister Benjamin Netanyahu has vowed Iran will pay for Tuesday's missile attack, and Washington said it would work with its longtime ally to ensure Iran faced "severe consequences".
Iranian President Masoud Pezeshkian, speaking in Doha, said on Thursday that Tehran would be ready to respond.
"Any type of military attack, terrorist act or crossing our red lines will be met with a decisive response by our armed forces," he said.
Israel's military told residents of more than 20 towns in south Lebanon to evacuate their homes on Thursday as it pressed on with a cross-border incursion.
The latest warnings took the number of southern towns subject to evacuation calls to 70 and included the provincial capital Nabatieh, suggesting another Israeli military operation was imminent against Hezbollah.
Beirut's southern suburb of Dahiye was hit by more than a dozen Israeli airstrikes on Thursday, Lebanese security sources and residents said.
Dahiye has been pummelled by Israeli bombs, including missiles that killed Nasrallah a week ago and flattened an entire block. Some of Thursday night's strikes hit close to Beirut's international airport, which borders Dahiye, a Reuters witness said.
Israel has sent troops into southern Lebanon after two weeks of air strikes in a worsening conflict. (AP PHOTO)
Hezbollah also carried out new strikes, targeting what it called Israel's "Sakhnin base" for military industries in Haifa Bay on the Mediterranean coast of northern Israel with a salvo of rockets.
Warning sirens sounded there again late on Thursday, as well as in the northern Israeli area of Galilee, and 10 projectiles crossed into Israel from Lebanon, Israel's military said. They were either intercepted or allowed to fall in open areas.
Late on Thursday, Hezbollah said it also targeted Israel's "Nesher base" in Haifa with a salvo of Fadi 2 rockets.
Israel, which has been fighting Hamas in the Palestinian territory of Gaza for almost a year, sent troops into southern Lebanon on Tuesday after two weeks of intense air strikes in a worsening conflict that has drawn in Iran and risks involving the United States.
The Group of Seven nations, which includes the US, Britain and allies, on Thursday condemned Iran's missile attack and reaffirmed their commitment to Israel's security.
But the group also called for restraint, a ceasefire in Gaza and halt to hostilities in Lebanon.
"A dangerous cycle of attacks and retaliation risks fuelling uncontrollable escalation in the Middle East, which is in no one's interest," the group said in a statement.
Qatar's Emir Sheikh Tamim bin Hamad Al-Thani also urged serious ceasefire efforts to stop what he called Israel's aggression.
