Live updates: Follow the latest news on Israel-Gaza
US President Joe Biden spoke to Saudi Crown Prince Mohammed bin Salman on Tuesday to discuss efforts to deter a regional spillover of the Israel-Gaza war, the White House said.
The call came amid growing US concerns that Iran-backed groups such as Hezbollah are seeking to escalate the conflict and attack American troops at military bases in the Middle East.
“The two leaders agreed on pursuing broader diplomatic efforts to maintain stability across the region and prevent the conflict from expanding,” the White House said in a statement.
Pentagon Press Secretary Brig Gen Patrick Ryder said there had been 10 attacks on forces in Iraq and three in Syria in the past week.
Biden administration officials have repeatedly warned of the risk of more attacks on US troops and of Iran seeking to widen the conflict.
“It's potentially a dangerous environment and we're taking it very, very seriously,” White House National Security spokesman John Kirby told reporters on Tuesday.
“Our commanders on the ground have the right to defend themselves, take and are taking the appropriate force protection measures.”
The US is bolstering its military presence in the region, moving an aircraft carrier and attack ships to the Arabian Gulf. It has also sent advanced missile defence systems.
The move, Mr Kirby said was “to make sure that we send a strong signal not only difference but a willingness to protect and defend ourselves and our national interests”.
The development comes as Israel has been bombarding the Gaza Strip with retaliatory air strikes that have killed more than 5,000 people.
The US, which has voiced staunch support for Israel, has also been trying to advocate the entry of humanitarian aid into the tiny enclave that is home to 2.3 million people.
But as Israel tightened its siege on Gaza, it has prevented the entry of water, fuel, food and medicine.
Three small convoys carrying critical aid have so far made their way to the strip following diplomatic efforts, but Israel has not allowed the entry of fuel.
Israel is thought to be preparing for a ground invasion of the Gaza Strip with the aim of destroying Hamas.
Meanwhile, the US has vetoed two UN Security Council resolutions calling for a ceasefire.
“A ceasefire right now would only benefit Hamas,” Mr Kirby said.
The major escalation dealt a blow to efforts by the Biden administration to forge a landmark normalisation deal between Israel and Saudi Arabia under the Abraham Accords.
As the conflict rages on, the White House said efforts towards achieving peace between Israelis and Palestinians would resume “as soon as the crisis subsides”.