Live updates: Follow the latest news on Israel-Gaza
The US believes there is a “likelihood” of Iran and its proxies escalating violence in the broader Middle East as it warned that an Israeli ground invasion of Gaza could present “a bit more difficult” of a fight.
US Secretary of State Antony Blinken said on Sunday that Washington is working to avoid a “second or third” front, but is preparing for the “likelihood” of escalation.
“We don't want escalation. If we don't want to see a second or third front develop. We don't want to see our forces or our personnel come under fire, but if that happens, we're ready for it,” he told NBC's Meet the Press.
US forces in western Iraq faced fresh attacks on Sunday after a string of reported drone and rocket attacks on US bases in Iraq and Syria.
The attacks, an almost regular occurrence since the end of the US-led war on ISIS wound down in 2018, have spiked in the wake of the Israel-Gaza war.
Mr Blinken added that Hamas is preventing Americans in Gaza from leaving through the Rafah border crossing into Egypt.
“Hamas has blocked them from leaving, showing once again its total disregard for civilians of any kinds who are stuck in Gaza,” he told CBS' Face the Nation in a separate Sunday interview.
Meanwhile, Washington over the weekend boosted its military readiness in the Middle East, ordering air defences throughout the region to be activated and alerting additional forces that they may be needed soon.
US Secretary of Defence Lloyd Austin warned that a looming Israeli ground incursion into Gaza “may be a bit more difficult” in part due to “the underground network of tunnels that Hamas has constructed over time”.
Hamas has “had a long time to prepare for a fight. So I think you'll see a fight that's characterised by a lot of IEDs, a lot of booby traps, and just really grinding activity going forward,” Mr Austin told ABC on Sunday.
The comments came after another deadly day in Gaza, with more than 250 Palestinians killed in just a 24-hour window.
Israeli air strikes kill more than 250 Palestinians in 24 hours
The Health Ministry said Israeli air strikes killed 266 people, mostly targeting Gaza's southern strip, where the army has told people to flee from the north.
About 112 children were killed since yesterday afternoon, it added.
Mr Austin sidestepped questions about a statement from Jordan King Abdullah's, a stalwart US ally, calling Israel's actions a “war crime,” and repeated the US claim that it converses with the Israelis frequently about acting per international law.
“The right thing to do is to make sure that we account for civilians in our [military operations] planning, that we provide corridors for [Palestinian] movement out of the battle space, that we are not destroying protected properties and where possible, and I think Israelis have been doing this for some time,” he said.
The Israelis “are a professional force and we will continue to encourage them to make sure that they're doing things in accordance with the law of war,” he added.
Meanwhile, the first convoy deliveries of fuel and humanitarian aid entered through the Rafah crossing in Egypt this weekend.
Mr Blinken added that “some water” had been turned back on in Gaza, and that Washington remains concerned about the spread of disease there due to the drinking of dirty water.
Mr Biden on Sunday reiterated that he has discussed with Israeli Prime Minister Benjamin Netanyahu that “Israel must operate by the laws of war”.
“We can’t ignore the humanity of innocent Palestinians who only want to live in peace,” Mr Biden posted on X, after requesting $100 billion for Israel as it continues its counter-offensive in Gaza.
