Biden told reporters at the White House however that he was not expecting Israel to launch any retaliation for Tehran's missile barrage on Israel before Thursday at least.
When asked by a reporter if he supported Israel striking Iran's oil facilities, Biden said "we're discussing that. I think that would be a little... anyway." Oil prices jumped five per cent over concerns about the Middle East after Biden spoke.
A rise in oil prices could be hugely damaging for Biden's Vice President Kamala Harris as the Democrat confronts Republican former president Donald Trump in a November 5 election where the cost of living is a major issue.
Biden said he did not expect any immediate action from Israel -- even if Israeli Prime Minister Benjamin Netanyahu has recently paid little heed to calls for restraint as he targets the Iran-allied Hezbollah militia in Lebanon.
"First of all, we don't 'allow' Israel, we advise Israel. And there is nothing going to happen today," Biden told reporters when asked if he would allow Israel to retaliate against Iran.
Biden said on Wednesday that he would not back Israel attacking Iranian nuclear sites. Iran launched around 200 rockets in a direct missile attack on Israel on Tuesday, prompting Netanyahu to warn that Tehran would pay.
Iran said it was in retaliation for the killing of Hassan Nasrallah, the leader of Hezbollah. Hezbollah has been launching rockets at Israel since shortly after the October 7, 2023 attacks on Israel by Iran's Palestinian ally Hamas, and Israel's crushing retaliatory offensive in Gaza.