The United States has warned that conflict between Israel and Palestinian group Hamas -- designated a terrorist organization by the U.S. and EU -- could expand into the wider Middle East, engulfing the oil-rich region in fighting.
U.S. national-security adviser Jake Sullivan said on October 15 that there was a risk that Lebanese group Hizballah or Iran could get directly involved in Israel's war with Hamas.
"There is a risk of an escalation of this conflict, the opening of a second front in the north, and of course of Iran's involvement," he told CBS's Face The Nation.
Sullivan said he was foremost concerned about Lebanon-based Hizballah attacking Israel from the north.
There have been minor skirmishes over the past week between Hizballah, an Iranian-backed militant group, and Israeli forces.
Meanwhile, Iranian Foreign Minister Hossein Amirabdollahian warned Israel against invading the Gaza Strip, saying Tehran would not "remain a spectator" in such a situation
Israeli forces have been pounding the Gaza Strip for days as they prepare for a ground invasion to wipe out Hamas, which rules the enclave.
Israel declared war on Hamas on October 8, a day after its militants invaded southern Israel, killing more than 1,000 people in the deadliest attack in the country's history.
Israel has said it can fight on two fronts should Hizballah attack.
Sullivan said the Biden administration will push Congress this week to pass an emergency spending bill that includes billions of dollars in military aid for Israel.
He said the administration also ordered a second aircraft-carrier strike group to the eastern Mediterranean near Israel to deter Hizballah or Iran from joining the conflict.
While the United States has not had formal diplomatic relations with Iran since 1980, Sullivan said the White House has means of communicating privately with Iran.
"We have availed ourselves of those means over the past few days to make clear privately that which we have said publicly," he said.
French President Emmanuel Macron spoke directly with his Iranian counterpart, Ebrahim Raisi, on October 15 to also warn Tehran from “extension of the conflict, especially to Lebanon.”
In the meantime, U.S. Secretary of State Antony Blinken has been on a whirlwind tour through Middle East capitals as the Biden administration seeks to contain the conflict, find a resolution, and help Gaza refugees.
Blinken will return to Israel on October 16 following visits to Qatar, Jordan, Bahrain, the United Arab Emirates, Saudi Arabia, and Egypt.
"There's a determination in every country I went to, to make sure that this conflict doesn't spread," Blinken said on October 15 as he prepared to leave Cairo. "They are using their own influence, their own relationships, to try to make sure that this doesn't happen."
The Middle East accounts for about 30 percent of the world's oil production and expansion of the conflict could drive prices above $100 a barrel at a time when the world is struggling to contain inflation.