Earlier this month, Defense Secretary Lloyd Austin ordered additional combat aircraft and missile-shooting warships to the region.

Two aircraft carriers — the USS Theodore Roosevelt and the USS Abraham Lincoln — and their accompanying warships and attack planes are now in or near the Gulf of Oman. Austin also made public his order to send the attack submarine USS Georgia to the region, an unusual move as the Pentagon seldom talks about the movements of its submarine fleet. The Georgia can fire cruise missiles and carry teams of Navy SEAL commandos.

The orders came in response to threats from Iran and its proxies in the Gaza Strip, Lebanon and Yemen to attack Israel to avenge the assassination of a top Hamas leader, Ismail Haniyeh, in Tehran, Iran, on July 31.

While the U.S. has said these moves are to help defend Israel and avert a wider regional war, a senior U.S. official said Saturday night that the U.S. military was better positioned to address a threat from Iran, and that the Israeli military would shoulder the bulk of any defense from attacks carried out by Hezbollah across the border in Lebanon.

This article originally appeared in The New York Times.

The troops were crew members of an MH-60 Black Hawk helicopter that was on a refueling training mission late Friday when the aircraft crashed off the coast of Cyprus, three U.S. officials said, speaking on the condition of anonymity to discuss operational details. The crash is under investigation, they said.

The Pentagon has quietly dispatched to Cyprus commando teams from the Joint Special Operations Command, including the Army’s Delta Force and the Navy’s SEAL Team 6, to stand by in case they are needed to help evacuate American citizens from the region.

SEAL Team 6 is based in Virginia Beach.

The commandos are also trained in hostage rescue operations. About a dozen or so American hostages were seized when Hamas attacked Israel on Oct. 7, but Biden administration officials have indicated they have no plans to put American boots on the ground in the densely populated Gaza Strip, where the Israel military is now conducting major ground operations.

The helicopter crew members who died were part of the Army’s elite 160th Special Operations Aviation Regiment, known as the Night Stalkers, and are among the aviators assigned to ferry the commandos on clandestine missions.

A U.S. aircraft carrier, the Gerald R. Ford, is also operating in the eastern Mediterranean off the coast of Israel, in what the Biden administration has said is a deterrent to Iran and its proxies in the region to widen the Israel-Hamas war.

In a statement Sunday, the military’s European Command acknowledged the deaths of the five service members in what it said was “a routine air refueling mission,” but released no other information about the crash, the crew or its unit in a reflection of the secrecy surrounding the unit’s mission.

Defense Secretary Lloyd Austin said in a statement Sunday, “We mourn the tragic loss of five U.S. service members during a training accident in the Mediterranean Sea.”

President Joe Biden, noting that it was Veterans Day weekend, said: “Our service members put their lives on the line for our country every day. They willingly take risks to keep the American people safe and secure.”

This article originally appeared in The New York Times.